JP5948134B2 - Scanning probe microscope and control method thereof - Google Patents

Description

  The present invention relates to a scanning probe microscope.

  A scanning probe microscope (SPM) is a generic name for a scanning microscope that acquires information on the surface of a sample while scanning a mechanical probe and displays the mapping. The SPM includes a scanning tunneling microscope (STM), an atomic force microscope (AFM), a scanning magnetic force microscope (MFM), a scanning near-field light microscope (SNOM), and the like.

  AFM is the most widely used in SPM. A cantilever having a mechanical probe at its free end, an optical displacement sensor for detecting the displacement of the cantilever, and a scanning for relatively scanning the mechanical probe and the sample. The mechanism is provided as a main element. Since the optical displacement sensor has a simple configuration and high detection sensitivity, an optical lever type optical displacement sensor is most widely used. This optical lever type optical displacement sensor irradiates a light beam with a diameter of several μm to several tens of μm on the cantilever, and changes the reflection direction of the reflected light according to the change of the cantilever warp by using a two-split optical detector or the like. By capturing, an electrical signal reflecting the operation of the mechanical probe at the free end of the cantilever is output. The AFM uses the scanning mechanism to control the relative distance between the mechanical probe and the sample in the XY direction while controlling the relative distance between the mechanical probe and the sample in the Z direction so that the output of the optical displacement sensor becomes constant. By scanning, the uneven state of the sample surface is mapped and displayed on a computer monitor.

  AFM often employs a method (AC mode) in which a cantilever is vibrated and an interaction between a sample and a probe is detected from its vibration characteristics. This is because there is an advantage that the force acting between the sample and the probe can be kept weak as compared with the normal method (called contact mode). In this AC mode AFM, the vibration of the cantilever caused by the interaction between the sample and the probe, that is, one of the amplitude change or phase change of the displacement is detected, and the surface shape of the sample is measured based on the detection result.

  Japanese Patent Application Laid-Open No. 2008-232984 discloses one such AC mode AFM. The AC mode AFM is configured to detect by switching one of the amplitude change and the phase change.

JP 2008-232984 A

  In the AC mode AFM, the interaction between the sample and the probe often detects a vibration state change (amplitude change or phase change) in a repulsive region, and forms an image based on the change. The amplitude of the cantilever displacement decreases as the repulsion between the sample and the probe increases. The phase of the cantilever displacement advances as the repulsion increases. The change in amplitude has a large change rate in a hard sample and a small change rate in a soft sample. That is, the amplitude change detection sensitivity is high for a hard sample and low for a soft sample. On the contrary, the change rate of the phase is small for a hard sample compared to the amplitude change, and the change rate is high for a soft sample compared to the amplitude change. That is, the phase change detection sensitivity is low for a hard sample and high for a soft sample. Conventional AC mode AFM detects repulsive force based on either amplitude change or phase change, so for samples containing both hard and soft parts, both hard and soft parts It is difficult to detect repulsive force with high sensitivity. This not only reduces the measurement accuracy, but also makes the control unstable.

  The present invention has been made in view of such a current situation, and an object of the present invention is to provide a scanning probe capable of stably measuring the surface shape of a sample in which a hard portion and a soft portion are mixed with high accuracy. To provide a microscope.

  A scanning probe microscope according to the present invention includes a cantilever having a probe at a free end, a scanning unit that relatively moves the probe and a sample in three dimensions, and an excitation unit that vibrates the cantilever based on an excitation signal. And a displacement detector that detects the displacement of the cantilever and outputs a displacement signal representing the displacement, and further detects amplitude information of the displacement signal and outputs an amplitude signal including the amplitude information. An amplitude information detection unit; and a phase difference information detection unit that detects phase difference information between the excitation signal and the displacement signal and outputs a phase signal including the phase difference information, and is a mixture of the amplitude signal and the phase signal. A hybrid signal generator that generates a signal, and a controller that controls the distance between the probe and the sample based on the hybrid signal. The hybrid signal generator is configured to adjust a hybrid ratio between the amplitude signal and the phase signal.

  ADVANTAGE OF THE INVENTION According to this invention, the scanning probe microscope which can measure the surface shape stably with high precision also with respect to the sample in which a hard part and a soft part are mixed is provided.

The structure of the scanning probe microscope of 1st embodiment is shown. The structure of the hybrid signal generation part in 1st embodiment is shown. -Shows the relationship between Asin φ and φ. The modification of the hybrid signal production | generation part in 1st embodiment is shown. The structure of the hybrid signal generation part in 2nd embodiment is shown. The relationship between A cos φ and φ is shown. -Shows the relationship between Asin φ and φ. The structure of the scanning probe microscope of 3rd embodiment is shown. The structure of the hybrid signal generation part in 3rd embodiment is shown. The modification of the scanning probe microscope of 3rd embodiment is shown. The example of information display (image of z control signal) in the scanning probe microscope of a third embodiment is shown. The example of information display (image of A) in the scanning probe microscope of a third embodiment is shown. The example of information display in the scanning probe microscope of a third embodiment (image of -Asinφ) is shown. The structure of the scanning probe microscope of 4th embodiment is shown. The structural example of the hybrid signal generation part in 4th embodiment is shown. The another structural example of the hybrid signal generation part in 4th embodiment is shown.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<First embodiment>
The configuration of the scanning probe microscope of the present embodiment is shown in FIG. As shown in FIG. 1, the scanning probe microscope has a cantilever 12 having a probe 11 at a free end. The cantilever 12 can be held by the holder 13 so as to face the sample 19.

  The scanning probe microscope also has a displacement detector 15 that detects the displacement of the cantilever 12 and outputs a displacement signal representing the displacement. The displacement detection unit 15 includes an optical lever type optical displacement sensor, and receives a laser light source 16 that irradiates a laser beam focused on the back surface of the cantilever 12 and a laser beam reflected from the back surface of the cantilever 12. The division detector 17 and an operational amplifier 18 that generates a displacement signal of the cantilever 12 from the output of the division detector 17 are configured.

  The scanning probe microscope also includes a vibration unit 14 that vibrates the cantilever 12 based on the vibration signal, and a hybrid signal generation unit 30 that supplies the vibration signal to the vibration unit 14. The vibration part 14 is provided in the holder 13, for example. The vibration unit 14 is made of, for example, a piezoelectric element, and can vibrate the cantilever 12 with a predetermined amplitude at a frequency near its mechanical resonance frequency. The hybrid signal generator 30 can generate a hybrid signal from the displacement signal output from the displacement detector 15 in addition to outputting the excitation signal. Details of the hybrid signal will be described later. The scanning probe microscope also includes a hybrid signal gain adjustment unit 28 that can adjust the gain of the hybrid signal output from the hybrid signal generation unit 30.

  The scanning probe microscope also has a scanning unit 20 that relatively moves the sample 19 and the probe 11 in three dimensions. The scanning unit 20 includes a Z scanner 21 and an XY scanner 22. The Z scanner 21 is disposed on the XY scanner 22, and the sample 19 can be placed on the Z scanner 21 via a sample table (not shown). The Z scanner 21 is driven by a Z driver 23 and can move the sample 19 in the Z direction with respect to the probe 11. The XY scanner 22 is driven by the XY driver 24 and can move the sample 19 in the XY direction with respect to the probe 11.

  The scanning probe microscope also includes a controller 25 that controls the Z driver 23 and the XY driver 24, and a host computer 27 that forms an image of the surface of the sample 19. The controller 25 can generate an XY scanning signal for two-dimensionally scanning the probe 11 along the surface of the sample 19 and a Z control signal for controlling the distance between the probe 11 and the sample 19. The controller 25 has a Z control unit 26 that generates a Z control signal from the hybrid signal. The host computer 27 can form an image of the surface of the sample 19 using the XY scanning signal and the Z control signal generated by the controller 25.

  The configuration of the hybrid signal generation unit 30 is shown in FIG. As shown in FIG. 2, the hybrid signal generation unit 30 includes a signal generator 34, an amplitude information detection unit 31, a phase difference information detection unit 32, an amplitude signal gain adjustment unit 36, a phase signal gain adjustment unit 37, and a calculation unit 35. It is configured.

  The signal generator 34 generates an excitation signal that causes the cantilever 12 to vibrate with a predetermined amplitude at a frequency near its mechanical resonance frequency, and outputs this to the excitation unit 14. The signal generator 34 also supplies a synchronization signal synchronized with the excitation signal to the phase difference information detection unit 32. This synchronization signal can be composed of, for example, a square wave signal (logic signal) having the same frequency and the same phase as the excitation signal.

  The amplitude information detection unit 31 detects amplitude information of the displacement signal of the cantilever 12 output from the displacement detection unit 15, generates an amplitude signal including the amplitude information, and outputs the amplitude signal.

The amplitude signal gain adjustment unit 36 can adjust the gain of the amplitude signal output from the amplitude information detection unit 31. Amplitude signal gain adjustment unit 36, for example, outputs an amplitude signal outputted from the amplitude information detector 31 and amplified by the gain G _A.

  The phase difference information detection unit 32 detects the phase difference information between the displacement signal of the cantilever 12 output from the displacement detection unit 15 and the synchronization signal supplied from the signal generator 34, and generates a phase signal including the phase difference information. Output. Since the synchronization signal and the excitation signal have the same frequency and phase, the phase difference between the displacement signal and the synchronization signal is equivalent to the phase difference between the displacement signal and the excitation signal.

  The phase difference information detection unit 32 includes a phase adjustment unit 33 that can adjust the phase of the synchronization signal supplied from the signal generator 34. The phase adjustment unit 33 can give a desired phase offset to the phase of the synchronization signal supplied from the signal generator 34. Therefore, the phase adjustment unit 33 can give a desired phase offset to the phase difference between the displacement signal and the synchronization signal. The phase difference information detection unit 32 generates and outputs a phase signal including information on the phase difference between the synchronization signal given the phase offset and the displacement signal. The phase difference between the synchronization signal to which the phase offset is given and the displacement signal is equivalent to the phase difference given to the phase difference between the displacement signal and the synchronization signal.

The phase signal gain adjustment unit 37 can adjust the gain of the phase signal output from the phase difference information detection unit 32. For example, the phase signal gain adjustment unit 37 amplifies the phase signal output from the phase difference information detection unit 32 with the gain _GΦ and outputs the amplified signal.

  The hybrid signal generation unit 30 is configured to be able to independently adjust the gain of the amplitude signal and the gain of the phase signal.

  The computing unit 35 adds the amplitude signal output from the amplitude signal gain adjusting unit 36 and the phase signal output from the phase signal gain adjusting unit 37, and outputs the result as a hybrid signal. Here, the addition processing includes negative addition processing, so-called subtraction processing.

  Here, the signal processing of the hybrid signal generation unit 30 will be described in detail.

Let the vibration signal be A ₀ sin ω ₀ t. Here, A ₀ is the amplitude of the vibration signal, ω ₀ is the angular frequency of the vibration signal, and t is time. ω ₀ has a value approximately equal to 2π · f _{0 where} the resonance frequency of the cantilever 12 is f ₀ .

The synchronization signal is, for example, a square wave signal having the same frequency (that is, angular frequency ω ₀ ) and the same phase as the excitation signal.

The displacement signal of the cantilever 12 is set as Asin (ω ₀ t + φ ₀ + φ). Here, A is the amplitude of the displacement signal, φ ₀ is the initial phase difference of the displacement signal that exists when the probe 11 and the sample 19 are not in contact, and φ is that the probe 11 and the sample 19 are in contact with each other. This is the phase difference of the displacement signal generated. Hereinafter, this phase difference is referred to as a phase shift amount for convenience. When the probe 11 and the sample 19 are not in contact, φ is zero. A and φ are detection targets.

The phase adjustment unit 33 gives a phase offset (+ ψ) to the phase of the synchronization signal output from the signal generator 34. That is, the phase adjustment unit 33 shifts the phase of the synchronization signal by (+ ψ). This is equivalent to giving a phase offset (−ψ) to the phase difference between the displacement signal of the cantilever 12 and the synchronization signal (ie, the excitation signal). The phase difference information detection unit 32 includes a phase signal Acos (φ ₀ + φ−ψ including information on the phase difference between the displacement signal Asin (ω ₀ t + φ ₀ + φ) of the cantilever 12 and the synchronization signal given the phase offset (+ ψ). ) Is generated and output.

Preferably, the phase adjustment unit 33 shifts the phase of the synchronization signal by (φ ₀ −π / 2). That is, ψ = φ ₀ −π / 2. In this case, the phase signal output from the phase difference information detection unit 32 is Acos {φ ₀ + φ− (φ ₀ −π / 2)} = − A sin φ.

  FIG. 3 is a graph showing the relationship between -Asin φ and φ. As can be seen from this graph, -Asin φ is most sensitive (high sensitivity) to the change in the phase shift amount φ when φ = 0.

When the measurement part is hard, the amplitude of the displacement signal of the cantilever 12 changes more greatly than the phase. This amplitude decreases as the repulsive force acting between the sample 19 and the probe 11 increases. On the other hand, when the measurement portion is soft, the displacement signal of the cantilever 12 changes in phase more greatly than the amplitude. This phase advances as the repulsive force acting between the sample 19 and the probe 11 increases (shifts in the + φ direction). For this reason, it is preferable that the phase signal output from the phase difference information detection unit 32 changes sensitively near φ = 0 and decreases as φ advances in accordance with the change in amplitude. For this reason, the phase offset ψ is preferably set to ψ = φ ₀ −π / 2 so that the phase signal Acos (φ ₀ + φ−ψ) becomes −Asinφ.

As can be seen again with reference to FIG. 2, the amplitude information detector 31 detects the amplitude A of the displacement signal Asin (ω ₀ t + φ ₀ + φ) of the cantilever 12 and outputs an amplitude signal A representing the amplitude.

Amplitude signal gain adjustment unit 36, an amplitude signal A outputted from the amplitude information detector 31 and amplified by the gain G _A, as the amplitude signal, and outputs a G A _A.

The phase signal gain adjustment section 37, the phase signal output from the phase difference information detection unit 32 (-Asinφ) was amplified with the gain G _[Phi, as the phase signal, and outputs the -G _{Φ Asinφ.}

Calculating unit 35 adds the processing the amplitude signals _{G A} A and the phase signal _(-G Φ Asinφ), as mixed signal, and outputs the _{A (G A -G Φ sinφ)} .

The gain G _[Phi by the amplitude signal gain adjustment section 36 by the gain G _A and the phase signal gain adjusting unit 37, which adjusts the hybrid ratio of the amplitude signal A and the phase signal (-Asinfai), hardness measurement portion (soft It can be changed according to Gain G _A and the gain G base state of _Φ are both 1, i.e. the hybrid ratio is 1: 1. If the measurement part of the sample in which the hard part and the soft part are mixed is dominant, the ratio of the amplitude signal A is increased. For example, the mixing ratio of the amplitude signal A and the phase signal (−Asinφ) is set to 3: 1. For example, the gain _{G A} and the gain G _[Phi respectively 1.5 and 0.5. If the measurement part of the sample in which the hard part and the soft part are mixed is dominant, the ratio of the phase signal (−Asinφ) is increased. For example, the hybrid ratio of the amplitude signal A and the phase signal (−Asinφ) is set to 1: 3. For example, the gain _{G A} and the gain G _[Phi 0.5 and 1.5, respectively. The gain _{G A} and the gain G _[Phi, it is desirable to be able to adjust the ranges of 0-2.

  The hybrid signal output from the calculation unit 35 is supplied to the Z control unit 26 in the controller 25 via the hybrid signal gain adjustment unit 28 as shown in FIG. The Z control unit 26 generates a Z control signal for controlling the distance between the sample 19 and the probe 11 so as to keep the hybrid signal constant, and supplies this to the Z driver 23. The Z driver 23 controls the Z scanner 21 according to the supplied Z control signal. As a result, the distance between the sample 19 and the probe 11 is controlled so as to keep the hybrid signal constant.

  The controller 25 generates an XY scanning signal for two-dimensionally scanning the probe 11 along the surface of the sample 19 and supplies this to the XY driver 24. The XY driver 24 controls the XY scanner 22 in accordance with the supplied XY scanning signal. As a result, the probe 11 scans two-dimensionally along the surface of the sample 19.

  The controller 25 also supplies an XY scanning signal and a Z control signal to the host computer 27. The host computer 27 forms an image of the surface of the sample 19 using the XY scanning signal and the Z control signal, displays the image, and stores the image data.

In scanning probe microscope of the present embodiment, the repulsive force acting between the sample 19 and probe 11 detects the mixed signal _{G A A-G} Φ Asinφ, controls the distance between the sample 19 and the probe 11 on the basis thereof . When the measurement part is hard, the amplitude signal A changes greatly. That is, when the measurement portion is hard, the amplitude signal G _A A greatly changes. When the measurement part is soft, the phase signal (-Asinφ) changes greatly. That phase signal _(-G Φ Asinφ) largely changes when the measurement portion is soft. For this reason, even if a hard part and a soft part are mixed in the sample 19, the repulsive force acting between the sample 19 and the probe 11 can be detected with high sensitivity. Furthermore, the hybrid ratio of the amplitude signal A and the phase signal (-Asinφ) can be adjusted. By adjusting the hybrid ratio of the amplitude signal A and phase signal (-Asinφ) according to the hardness (softness) of the measurement part, how the hard part and the soft part are mixed is mixed. Even if it is, the optimal detection state can be obtained. As a result, the surface shape can be stably measured with high accuracy even for a sample in which a hard portion and a soft portion are mixed.

[Modification of First Embodiment]
As a modification of the first embodiment, a special usage pattern of the hybrid signal generation unit 30 will be described. A hybrid signal generation unit according to this modification is shown in FIG. The hybrid signal generation unit 30 in FIG. 4 differs from the hybrid signal generation unit 30 in FIG. 2 only in that the gain of the amplitude signal gain adjustment unit 36 is fixed to 1.

In this modification, the amplitude signal gain adjustment unit 36 does not amplify the amplitude signal A output from the amplitude information detection unit 31, in other words, amplifies the gain signal 1 and outputs A as an amplitude signal. Phase signal gain adjustment section 37, the phase signal output from the phase difference information detection unit 32 (-Asinφ) was amplified with the gain G _[Phi, as the phase signal, and outputs the -G _{Φ Asinφ.} Calculating unit 35 adds the processing the amplitude signal A and the phase signal _(-G Φ Asinφ), as mixed signal, and outputs the _{A (1-G Φ sinφ)} .

  In this modification, the gain of the amplitude signal gain adjustment unit 36 is fixed to 1, and the hybrid signal generation unit 30 can adjust only the gain of the phase signal by the phase signal gain adjustment unit 37. Adjustment of the mixing ratio of the amplitude signal and the phase signal is performed by changing the gain of the phase signal by the phase signal gain adjusting unit 37. For this reason, there exists an advantage that it is easy to adjust the hybrid ratio of an amplitude signal or a phase signal.

  However, on the other hand, for example, when the measurement part is soft and the gain of the phase signal gain adjustment unit 37 is extremely increased, there is a possibility that the feedback loop gain (control loop gain) will be adversely affected. In such a case, it is desirable to adjust (correct) the gain of the feedback loop by the hybrid signal gain adjusting unit 28.

  Fixing the gain of the amplitude signal gain adjusting unit 36 to 1 is equivalent to passing the amplitude signal without amplifying the amplitude signal in terms of a circuit. Therefore, the hybrid signal generation unit 30 may be configured to omit the amplitude signal gain adjustment unit 36 instead of fixing the gain of the amplitude signal gain adjustment unit 36 to 1.

  Here, a modification example is shown in which the gain of the amplitude signal gain adjustment unit 36 is fixed to 1. However, instead of fixing the gain of the amplitude signal gain adjustment unit 36 to 1, the gain of the phase signal gain adjustment unit 37 is set to 1. The modification which fixes is also possible, and the modification which abbreviate | omitted the phase signal gain adjustment part 37 is also possible. In this modification, adjustment of the mixing ratio of the amplitude signal and the phase signal is performed by changing the gain of the amplitude signal gain adjusting unit 36. This modification also has an advantage that it is easy to adjust the hybrid ratio of the amplitude signal and the phase signal.

  If this embodiment and its modification are put together, the hybrid signal generation part 30 should just be comprised so that at least one of the gain of an amplitude signal and the gain of a phase signal can be adjusted.

<Second embodiment>
The scanning probe microscope of the present embodiment is the same as the scanning probe microscope of the first embodiment except that the configuration of the hybrid signal generation unit is different. Therefore, here, description will be given with an emphasis on the configuration and operation of the hybrid signal generation unit of the present embodiment.

  FIG. 5 shows a configuration of the hybrid signal generation unit 40 of the present embodiment. As shown in FIG. 5, the hybrid signal generation unit 40 includes a signal generator 34, a phase difference information detection unit 41, a phase difference information detection unit 32, an amplitude signal gain adjustment unit 36, a phase signal gain adjustment unit 37, and a calculation unit 35. It is composed of

  Details of the signal generator 34, the phase difference information detection unit 32, the amplitude signal gain adjustment unit 36, the phase signal gain adjustment unit 37, and the calculation unit 35 are as described in the first embodiment.

  As can be seen by comparing FIG. 2 and FIG. 5, the hybrid signal generation unit 40 includes a phase difference information detection unit 41 in place of the amplitude information detection unit 31. 30. In other words, the hybrid signal generation unit 40 is configured by replacing the amplitude information detection unit 31 of the hybrid signal generation unit 30 of the first embodiment with a phase difference information detection unit 41.

  The signal generator 34 generates an excitation signal that causes the cantilever 12 to vibrate with a predetermined amplitude at a frequency near its mechanical resonance frequency, and outputs this to the excitation unit 14. The signal generator 34 also outputs a synchronization signal synchronized with the excitation signal to the phase difference information detection unit 41 and the phase difference information detection unit 32. This synchronization signal can be composed of, for example, a square wave signal (logic signal) having the same frequency and the same phase as the excitation signal.

  The phase difference information detection unit 41 generates and outputs a first phase signal including information on the phase difference between the displacement signal of the cantilever 12 supplied from the displacement detection unit 15 and the synchronization signal supplied from the signal generator 34. .

  The phase difference information detection unit 41 includes a phase adjustment unit 42 that can adjust the phase of the synchronization signal supplied from the signal generator 34. The phase adjustment unit 42 can give a desired phase offset to the phase of the synchronization signal supplied from the signal generator 34. Therefore, the phase adjustment unit 42 can give a desired phase offset to the phase difference between the displacement signal and the synchronization signal. The phase difference information detection unit 41 outputs a phase signal including information on the phase difference between the synchronization signal given the phase offset and the displacement signal.

  The phase difference information detection unit 32 generates and outputs a second phase signal including information on the phase difference between the displacement signal of the cantilever 12 supplied from the displacement detection unit 15 and the synchronization signal supplied from the signal generator 34. .

  The phase difference information detection unit 32 includes a phase adjustment unit 33 that can adjust the phase of the synchronization signal supplied from the signal generator 34. The phase adjustment unit 33 can give a desired phase offset to the phase of the synchronization signal supplied from the signal generator 34. Therefore, the phase adjustment unit 33 can give a desired phase offset to the phase difference between the displacement signal and the synchronization signal. The phase difference information detection unit 32 outputs a phase signal including information on the phase difference between the synchronization signal given the phase offset and the displacement signal.

  Here, since the frequency and the phase of the synchronization signal and the excitation signal are the same, the phase difference between the displacement signal and the synchronization signal is equivalent to the phase difference between the displacement signal and the excitation signal. Further, the phase difference between the synchronization signal to which the phase offset is given and the displacement signal is equivalent to the phase difference given to the phase difference between the displacement signal and the synchronization signal.

Amplitude signal gain adjustment section 36 amplifies the phase signal output from the phase difference information detection unit 41 by the amplification factor G _A, and outputs the result as the first phase signal.

The phase signal gain adjustment unit 37 amplifies the phase signal output from the phase difference information detection unit 32 with an amplification factor _Gφ , and outputs the result as a second phase signal.

  The computing unit 35 adds the first phase signal supplied from the amplitude signal gain adjusting unit 36 and the second phase signal supplied from the phase signal gain adjusting unit 37, and outputs this as a hybrid signal.

  Here, the signal processing of the hybrid signal generation unit 40 will be described in detail.

Let the vibration signal be A ₀ sin ω ₀ t. Here, A ₀ is the amplitude of the vibration signal, ω ₀ is the angular frequency of the vibration signal, and t is time. ω ₀ has a value approximately equal to 2π · f _{0 where} the resonance frequency of the cantilever 12 is f ₀ .

The synchronization signal is, for example, a square wave signal having the same frequency (that is, angular frequency ω ₀ ) and the same phase as the excitation signal.

The displacement signal of the cantilever 12 is set as Asin (ω ₀ t + φ ₀ + φ). Here, A is the amplitude of the displacement signal, φ ₀ is the initial value of the phase of the displacement signal when the probe 11 and the sample 19 are not in contact, and φ is due to the contact between the probe 11 and the sample 19. Phase shift amount of the displacement signal generated by the When the probe 11 and the sample 19 are not in contact, φ is zero. A and φ are detection targets.

The phase adjustment unit 42 gives a phase offset (+ ψ ₁ ) to the phase of the synchronization signal output from the signal generator 34. That is, the phase adjustment unit 42 shifts the phase of the synchronization signal by (+ ψ ₁ ). The phase difference information detection unit 32 includes a phase signal Acos (φ ₀ + φ− that includes information on the phase difference between the displacement signal Asin (ω ₀ t + φ ₀ + φ) of the cantilever 12 and the synchronization signal to which the phase offset (+ ψ ₁ ) is given. ψ ₁ ) is generated and output.

Preferably, the phase adjustment unit 42 shifts the phase of the synchronization signal by (+ φ ₀ ). That is, ψ ₁ = φ ₀ . In this case, the phase signal output from the phase difference information detection unit 41 is Acos (φ ₀ + φ−φ ₀ ) = A cos φ.

The phase adjustment unit 33 gives a phase offset (+ ψ ₂ ) to the phase of the synchronization signal output from the signal generator 34. That is, the phase adjustment unit 33 shifts the phase of the synchronization signal by (+ ψ ₂ ). The phase difference information detection unit 32 includes a phase signal Acos (φ ₀ + φ− including the information on the phase difference between the displacement signal Asin (ω ₀ t + φ ₀ + φ) of the cantilever 12 and the synchronization signal to which the phase offset (+ ψ ₂ ) is given. ψ ₂ ) is generated and output.

Preferably, the phase adjustment unit 33 shifts the phase of the synchronization signal by (φ ₀ −π / 2). That is, ψ ₂ = φ ₀ -π / 2. In this case, the phase signal output from the phase difference information detection unit 32 is Acos {φ ₀ + φ− (φ ₀ −π / 2)} = − A sin φ.

  FIG. 6 is a graph showing the relationship between A cos φ and φ. As can be seen from this graph, A cos φ is the least insensitive (low sensitivity) to the change in the phase shift amount φ when φ = 0.

  FIG. 7 is a graph showing the relationship between -Asin φ and φ. As can be seen from this graph, −A sin φ is most sensitive (high sensitivity) to a change in the phase shift amount φ when φ = 0, and decreases as the phase advances from zero. That is, the phase signal (−Asinφ) decreases as the repulsive force acting between the sample 19 and the probe 11 increases, similarly to the direction of change of the amplitude signal.

Amplitude signal gain adjustment unit 36, a phase signal Acosfai outputted from the phase difference information detection section 41 amplifies by the gain _{G A,} as a first phase _signal, and outputs a G A Acosφ.

Phase signal gain adjustment section 37, the phase signal output from the phase difference information detection unit 32 (-Asinφ) amplified by the gain G _phi, as a second phase signal, and outputs the -G _{φ Asinφ.}

The arithmetic unit 35 adds the first phase signal G _A Acos _φ and the second phase signal (−G _{φ A} sin φ) and outputs A (GA cos _φ −G _φ sin φ) as a hybrid signal.

The gain G _phi by the amplitude signal gain adjustment section 36 by the gain G _A and the phase signal gain adjusting unit 37, respectively, which adjusts the hybrid ratio of the first phase signal Acosφ and the second phase signal (-Asinφ) It can be changed according to the hardness (softness) of the measurement part. Basic state of the gain G _A and the gain G _phi are both 1, i.e. the hybrid ratio is 1: 1.

  By doing this, when the measurement object is hard, that is, when the amplitude change is larger than the phase shift amount φ, the signal change amount becomes A cos φ> −A sin φ, and the signal of A cos φ works dominantly. When the change of φ is small, cos φ≈1 can be set, so that Acos φ≈A, that is, the phase signal Acos φ can be regarded as substantially the same as the amplitude signal A.

  Further, when the measurement target is soft, that is, when the phase shift amount φ is larger than the change in amplitude, the change amount of the signal is −A sin φ> A cos φ, and the signal of −A sin φ works dominantly. At this time, since the change in φ is large, the change in Acos φ is also larger than in the first embodiment (in the case of only A).

Furthermore, if the measurement part of the sample in which the hard part and the soft part are mixed is dominant, the ratio of the first phase signal A cos φ is increased. For example, the hybrid ratio of the first phase signal Acosφ and the second phase signal (−Asinφ) is set to 3: 1. That gain _{G A} and the gain G _phi 1.5 respectively to 0.5. Further, if the measurement portion of the sample in which the hard portion and the soft portion are mixed is dominant, the ratio of the second phase signal (−Asinφ) is increased. For example, the hybrid ratio of the first phase signal Acosφ and the second phase signal (−Asinφ) is set to 1: 3. That 1.5 and gain _{G A} and the gain G _phi 0.5 respectively. The gain _{G A} and the gain G _phi, it is desirable to be able to adjust the ranges of 0-2.

  The hybrid signal output from the calculation unit 35 is supplied to the Z control unit 26 in the controller 25 as shown in FIG. The Z control unit 26 generates a Z control signal for controlling the distance between the sample 19 and the probe 11 so as to keep the hybrid signal constant, and supplies this to the Z driver 23. The Z driver 23 controls the Z scanner 21 according to the supplied Z control signal. As a result, the distance between the sample 19 and the probe 11 is controlled so as to keep the hybrid signal constant.

  The controller 25 generates an XY scanning signal for two-dimensionally scanning the probe 11 along the surface of the sample 19 and supplies this to the XY driver 24. The XY driver 24 controls the XY scanner 22 in accordance with the supplied XY scanning signal. As a result, the probe 11 scans two-dimensionally along the surface of the sample 19.

  The controller 25 also supplies an XY scanning signal and a Z control signal to the host computer 27. The host computer 27 forms an image of the surface of the sample 19 using the XY scanning signal and the Z control signal, displays the image, and stores the image data.

In scanning probe microscope of the present embodiment, the repulsive force acting between the sample 19 and probe 11 detects the mixed signal _{A (G A cosφ-G φ} sinφ), the distance between the sample 19 and the probe 11 on the basis thereof To control. When the measurement portion is hard, Acos φ can be regarded as almost A, and therefore the first phase signal G _A Acos φ changes greatly. As a result, for the hard part, the repulsive force acting between the sample 19 and the probe 11 can be detected with the same sensitivity as the first embodiment. When the measurement portion is soft, the second phase signal (−G _φ Asin _φ ) changes greatly, and the first phase signal G _A Acos φ also changes. As a result, for the soft part, the repulsive force acting between the sample 19 and the probe 11 can be detected with higher sensitivity than in the first embodiment. Furthermore, the hybrid ratio of the first phase signal Acosφ and the second phase signal (-Asinφ) can be adjusted according to the hardness (softness) of the measurement portion. By doing so, in the sample in which the hard part and the soft part are mixed, an optimum detection state can be obtained no matter how they are mixed. As a result, the surface shape can be stably measured with high accuracy even for a sample in which a hard portion and a soft portion are mixed.

  The scanning probe microscope of this embodiment can be modified in the same manner as the modification of the first embodiment shown in FIG.

<Third embodiment>
FIG. 8 shows the configuration of the scanning probe microscope of the present embodiment. 8, members denoted by the same reference numerals as those of the scanning probe microscope according to the first embodiment shown in FIG. 1 are the same members, and detailed description thereof is omitted. The difference from the scanning probe microscope of the first embodiment shown in FIG. 1 is that the scanning probe microscope of this embodiment includes a hybrid signal generator 50 instead of the hybrid signal generator 30, and an amplitude display unit. 51 and a phase display unit 52 are further provided.

  FIG. 9 shows the configuration of the hybrid signal generator 50 of this embodiment. 9, members denoted by the same reference numerals as those of the hybrid signal generation unit 30 shown in FIG. 2 are the same members, and detailed description thereof is omitted. As shown in FIG. 9, the hybrid signal generation unit 50 uses the amplitude signal A output from the amplitude information detection unit 31 and the phase signal (−Asinφ) output from the phase difference information detection unit 32 to the hybrid signal generation unit 50. Each is configured to output to the outside.

  The amplitude signal A and the phase signal (−Asinφ) output from the hybrid signal generation unit 50 are supplied to the amplitude display unit 51 and the phase display unit 52, respectively. The amplitude display unit 51 has a function of displaying information including amplitude information of the displacement signal, and the phase display unit 52 has a function of displaying information including information of the phase difference of the displacement signal. That is, the scanning probe microscope of the present embodiment is configured to monitor the amplitude signal A and the phase signal (−Asinφ). As a result, it is easy to determine the hardness (softness) state of the measurement part of the sample, and it is possible to easily adjust the hybrid ratio of the amplitude signal A and the phase signal (-Asinφ).

  The amplitude display unit 51 and the phase display unit 52 may be numerical meters, but an image monitor capable of displaying an image is desirable. Further, as shown in FIG. 10, the amplitude signal A and the phase signal (−Asin φ) are taken into the controller 60 as shown in FIG. 10 without providing the amplitude display unit 51 and the phase display unit 52 individually as shown in FIG. It is good also as a structure which displays an image.

  FIGS. 11, 12, and 13 show examples in which the Z control signal, the amplitude signal A, and the phase signal (−Asinφ) are displayed as images. FIG. 11 is an image showing the surface shape of the sample 19 obtained by the scanning probe microscope of the present embodiment. The dark gray area has a low height, and the white area protrudes. In the following description, the white area is called a convex part. FIG. 12 is a plot image of the amplitude signal A obtained simultaneously with the image acquisition of FIG. FIG. 13 is a plot image of the phase signal (−Asinφ) obtained simultaneously with the image acquisition of FIG.

  In the plot image of the amplitude signal A in FIG. 12, the convex portion of the sample is displayed high. This represents a phenomenon in which the signal level of the amplitude signal A increases at the convex portion. On the other hand, in the plot image of the phase signal (−Asinφ) in FIG. 13, the convex portion of the sample is displayed low. This represents a phenomenon in which the signal level of the phase signal (−Asinφ) becomes small at the convex portion.

  Both the amplitude signal A and the phase signal (−Asinφ) decrease as the repulsive force acting between the sample 19 and the probe 11 increases. When the sample 19 is hard, the amplitude signal A is more sensitive than the phase signal (-Asinφ). That is, the decrease rate of the amplitude signal A is larger than that of the phase signal (−Asinφ). When the sample 19 is soft, the phase signal (-Asinφ) is more sensitive than the amplitude signal A. That is, the decrease rate of the phase signal (−Asinφ) is larger than that of the amplitude signal A. From this, it can be seen that the sample is hard in the region where the signal level of the amplitude signal A is decreased, and the sample is soft in the region where the signal level of the phase signal (−Asinφ) is decreased. Therefore, in the image of the surface shape of the sample 19 in FIG. 11, it can be determined that the convex portion is softer than the dark gray region.

  Thus, by displaying and monitoring the amplitude signal A and the phase signal (-Asinφ), it becomes easy to judge the hardness (softness) state of the measurement portion of the sample. As a result, the amplitude signal A and the phase are determined. The hybrid ratio of the signal (−Asinφ) can be easily adjusted.

  In the scanning probe microscope of the present embodiment, control is performed so as to keep the mixed signal obtained by adding the amplitude signal and the phase signal constant, so if either the amplitude signal A or the phase signal (−Asinφ) decreases. The other will increase. Therefore, the same effect can be obtained by displaying only one of the amplitude signal A and the phase signal (−Asinφ).

<Fourth embodiment>
FIG. 14 shows the configuration of the scanning probe microscope of the present embodiment. 14, members denoted by the same reference numerals as those of the scanning probe microscope of the first embodiment shown in FIG. 1 are the same members, and detailed description thereof is omitted. The scanning probe microscope of the present embodiment is different from the scanning probe microscope of the first embodiment in that another hybrid signal generation unit 70 is provided instead of the hybrid signal generation unit 30.

[Configuration Example 1 of Hybrid Signal Generation Unit 70]
FIG. 15 shows one configuration example of the hybrid signal generation unit 70 of this embodiment. 15, members denoted by the same reference numerals as those of the hybrid signal generation unit 30 illustrated in FIG. 2 are similar members, and detailed description thereof is omitted.

  As shown in FIG. 15, the hybrid signal generator 70 includes an amplitude information detector 31, a phase difference information detector 32, a signal generator 34, a plurality of, for example, three amplitude signal amplifiers 71A, 72A, 73A, and a plurality of, for example, three Phase signal amplifiers 71B, 72B, 73B, a selector 74, and an arithmetic unit 35 are provided.

  Details of the amplitude information detection unit 31, the phase difference information detection unit 32, the signal generator 34, and the calculation unit 35 are as described in the first embodiment.

The amplitude signal amplifying units 71A, 72A and 73A amplify the amplitude signals output from the amplitude information detecting unit 31 with the gains G _A1 , G _A2 and G _A3 , respectively. The gains G _A1 , G _A2 and G _A3 are preset fixed values different from each other.

The phase signal amplifiers 71B, 72B, and 73B amplify the phase signals output from the phase difference information detector 32 with gains G _φ1 , G _φ2 , and G _φ3 , respectively, and output them. The gains G _φ1 , G _φ2 and G _φ3 are preset fixed values different from each other.

  The three amplitude signal amplifying units 71A, 72A, 73A and the three phase signal amplifying units 71B, 72B, 73B constitute three pairs, respectively.

  The selecting unit 74 is configured to select one of the amplitude signal amplifying units 71A, 72A, and 73A and one of the phase signal amplifying units 71B, 72B, and 73B constituting the pair according to a selection signal input from the controller 25. Has been. As a result, the selection unit 74 uses the amplitude signal amplified by the amplitude signal amplification unit 71A, the phase signal amplified by the phase signal amplification unit 71B, the amplitude signal amplified by the amplitude signal amplification unit 72A, and the phase signal amplification unit 72B. One of the amplified phase signal, the amplitude signal amplified by the amplitude signal amplifying unit 73A, and the phase signal amplified by the phase signal amplifying unit 73B is output at a time.

  The calculation unit 35 adds the amplitude signal and the phase signal output from the selection unit 74 and outputs the result as a hybrid signal. In other words, the calculation unit 35 includes the amplitude signal output from one of the amplitude signal amplification units 71A, 72A, 73A selected by the selection unit 74 and the phase signal amplification units 71B, 72B, 72B selected by the selection unit 74. The phase signal output from one of 73B is added.

  The hybrid signal generator 70 outputs the signal output from the calculator 35 as a hybrid signal.

[Configuration Example 2 of Hybrid Signal Generation Unit 70]
FIG. 16 shows another configuration example of the hybrid signal generation unit 70 of the present embodiment. 16, members denoted by the same reference numerals as the members of the hybrid signal generation unit 30 shown in FIG. 2 are the same members, and detailed description thereof is omitted.

  As shown in FIG. 16, the hybrid signal generation unit 70 includes an amplitude information detection unit 31, a phase difference information detection unit 32, a signal generator 34, a plurality of, for example, three amplitude signal amplification units 71A, 72A, 73A, and a plurality of, for example, three. Phase signal amplifiers 71B, 72B, 73B, a plurality of, for example, three arithmetic units 75, 76, 77, and a selector 78 are provided.

  Details of the amplitude information detector 31, the phase difference information detector 32, and the signal generator 34 are as described in the first embodiment.

The amplitude signal amplifying units 71A, 72A and 73A amplify the amplitude signals output from the amplitude information detecting unit 31 with the gains G _A1 , G _A2 and G _A3 , respectively. The gains G _A1 , G _A2 and G _A3 are preset fixed values different from each other.

The phase signal amplifiers 71B, 72B, and 73B amplify the phase signals output from the phase difference information detector 32 with gains G _φ1 , G _φ2 , and G _φ3 , respectively, and output them. The gains G _φ1 , G _φ2 and G _φ3 are preset fixed values different from each other.

Further, the gain _{G A1, G A2, G A3} and gain G _.phi.1, G _.phi.2, the ratio _G A1 / G _.phi.1 of _{G φ3, G A2 / G φ2} , G A3 / G φ3 is, one is less than 1, different Is set to be larger than 1.

  The three amplitude signal amplifying units 71A, 72A, 73A and the three phase signal amplifying units 71B, 72B, 73B constitute three pairs, respectively.

  The computing unit 75 adds the amplitude signal amplified by the amplitude signal amplifying unit 71A and the phase signal amplified by the phase signal amplifying unit 71B and outputs the result. The calculation unit 76 adds the amplitude signal amplified by the amplitude signal amplification unit 72A and the phase signal amplified by the phase signal amplification unit 72B and outputs the result. The computing unit 77 adds the amplitude signal amplified by the amplitude signal amplifying unit 73A and the phase signal amplified by the phase signal amplifying unit 73B and outputs the result.

  The selection unit 78 selects and outputs one of a plurality of signals output from the calculation units 75, 76, and 77 according to the selection signal input from the controller 25.

  The hybrid signal generator 70 outputs the signal output from the selector 78 as a hybrid signal.

In both the configuration example of FIG. 15 and the configuration example of FIG. 16, the hybrid signal generation unit 70 has gains G _A1 , G _A2 , G _A3 and gains G _φ1 , G _.phi.2, amplified by G _.phi.3, gain _{G A1, G A2,} the amplitude signal and the gain G _.phi.1 amplified by one _{G A3, G φ2,} to addition processing one by amplified phase signal G _.phi.3 It is configured as follows.

[Signal Processing of Hybrid Signal Generation Unit 70]
The details of the signal processing of the hybrid signal generator 70 are the same as the signal processing of the hybrid signal generator 30. A brief description is given below.

Let the vibration signal be A ₀ sin ω ₀ t. Here, A ₀ is the amplitude of the vibration signal, ω ₀ is the angular frequency of the vibration signal, and t is time. The synchronization signal is, for example, a square wave signal having the same frequency (that is, angular frequency ω ₀ ) and the same phase as the excitation signal.

The displacement signal of the cantilever 12 is set as Asin (ω ₀ t + φ ₀ + φ). Here, A is the amplitude of the displacement signal, φ ₀ is the initial phase difference of the displacement signal that exists when the probe 11 and the sample 19 are not in contact, and φ is that the probe 11 and the sample 19 are in contact with each other. This is the phase difference of the displacement signal generated.

The phase adjustment unit 33 gives a phase offset (+ ψ) to the phase of the synchronization signal output from the signal generator 34. The phase difference information detection unit 32 includes a phase signal Acos (φ ₀ + φ−ψ including information on the phase difference between the displacement signal Asin (ω ₀ t + φ ₀ + φ) of the cantilever 12 and the synchronization signal given the phase offset (+ ψ). ) Is generated and output.

Preferably, the phase adjustment unit 33 shifts the phase of the synchronization signal by (φ ₀ −π / 2). That is, ψ = φ ₀ −π / 2. In this case, the phase signal output from the phase difference information detection unit 32 is Acos {φ ₀ + φ− (φ ₀ −π / 2)} = − A sin φ.

The amplitude information detector 31 detects the amplitude A of the displacement signal Asin (ω ₀ t + φ ₀ + φ) of the cantilever 12 and outputs an amplitude signal A representing the amplitude.

The amplitude signal amplifying units 71A, 72A, 73A amplify the amplitude signal output from the amplitude information detecting unit 31 with gains G _A1 , G _A2 , G _A3 , respectively, and G _A1 A, G _A2 A, G _A3 A is output.

The phase signal amplifiers 71B, 72B, and 73B amplify the phase signals output from the phase difference information detector 32 with gains G _φ1 , G _φ2 , and G _φ3 , respectively, and −G _φ1 Asin _φ , −G as phase signals. _φ2 Asinφ, -G _φ3 Asinφ are output.

The gains G _A1 , G _A2 , and G _{A3 of the} amplitude signal amplifying units 71A, 72A, and 73A and the phase signals of the phase signal amplifying units 71B, 72B, and 73B are the gains G _φ1 , G _φ2 , and G _φ3 , respectively. Three hybrid ratios of the phase signal (−Asinφ) are defined. Further, the hybrid ratio _{G A1 / G φ1, G A2} / G φ2, when the _G A3 / _{G φ3,} one hybrid ratio is less than 1, different one is greater than 1.

Mixed signal generation unit 70 by the selection unit 74 and the arithmetic unit 35, or by the selection unit 78 and the arithmetic unit _{75,76,77, A (G A1 -G φ1} sinφ), A (G A2 -G φ2 sinφ) , A (G _A3 -G _φ3 sin φ) is output as a hybrid signal. In other words, the hybrid signal generator 70 is configured to hybridize the amplitude signal and the phase signal at one of three preset hybrid ratios.

  The hybrid ratio of the amplitude signal A and the phase signal (-Asinφ) is selected according to the hardness (softness) of the measurement part. In other words, the hybrid signal output from the hybrid signal generation unit 70 is switched. If the measurement portion of the sample in which the hard portion and the soft portion are mixed is dominant, the selection signal for mixing the amplitude signal and the phase signal with a high ratio of the amplitude signal A is sent to the hybrid signal generation unit 70. . Moreover, if the measurement part of the sample in which the hard part and the soft part are mixed is dominant, the selection signal that hybridizes the amplitude signal and the phase signal with a high ratio of the phase signal (−Asinφ) is mixed signal. The data is sent to the generation unit 70.

  The hybrid signal output from the hybrid signal generator 70 is supplied to the Z controller 26 in the controller 25 via the hybrid signal gain adjuster 28 as shown in FIG. The Z control unit 26 supplies a Z control signal for controlling the distance between the sample 19 and the probe 11 to the Z driver 23 so as to keep the hybrid signal constant. The Z driver 23 controls the Z scanner 21 according to the supplied Z control signal. As a result, the distance between the sample 19 and the probe 11 is controlled so as to keep the hybrid signal constant.

  The controller 25 supplies the XY driver 24 with an XY scan signal for two-dimensionally scanning the probe 11 along the surface of the sample 19. The XY driver 24 controls the XY scanner 22 in accordance with the supplied XY scanning signal. As a result, the probe 11 scans two-dimensionally along the surface of the sample 19.

  The controller 25 also supplies an XY scanning signal and a Z control signal to the host computer 27. The host computer 27 forms an image of the surface of the sample 19 using the XY scanning signal and the Z control signal, displays the image, and stores the image data.

In scanning probe microscope of the present embodiment, the repulsive force acting between the sample 19 and probe 11 detects the mixed signal _{A (G A -G Φ sinφ)} , the distance between the sample 19 and the probe 11 on the basis thereof Control. When the measurement part is hard, the amplitude signal A changes greatly. That is, when the measurement portion is hard, the amplitude signal G _A A greatly changes. When the measurement part is soft, the phase signal (-Asinφ) changes greatly. That phase signal _(-G Φ Asinφ) largely changes when the measurement portion is soft. For this reason, even if a hard part and a soft part are mixed in the sample 19, the repulsive force acting between the sample 19 and the probe 11 can be detected with high sensitivity. Furthermore, the hybrid ratio of the amplitude signal A and the phase signal (−Asinφ) can be changed between a plurality of preset hybrid ratios. By changing the mixing ratio of the amplitude signal A and phase signal (-Asinφ) according to the hardness (softness) of the measurement part, how the hard part and the soft part are mixed is mixed. Even if it is, the optimal detection state can be obtained. As a result, the surface shape can be stably measured with high accuracy even for a sample in which a hard portion and a soft portion are mixed.

  In the description so far, the hybrid signal generation unit 70 amplifies both the amplitude signal and the phase signal with the preset gains GA1, GA2, and GA3 and the gains Gφ1, Gφ2, and Gφ3, and the gains GA1, GA2, and GA3. The amplitude signal amplified by one and the phase signal amplified by one of the gains Gφ1, Gφ2, and Gφ3 are added, but similar to the modification of the first embodiment shown in FIG. Can be modified. That is, a modification in which the gain of any one of the amplitude signal amplification units 71A, 72A, 73A and the phase signal amplification units 71B, 72B, 73B is fixed to 1, or the amplitude signal amplification units 71A, 72A, 73A and the phase signal amplification unit 71B. , 72B, and 73B may be omitted. In other words, the hybrid signal generation unit 70 amplifies one of the amplitude signal and the phase signal with a plurality of preset gains, and one of the amplitude signal and the phase signal amplified with one of these gains. The other of the signal and the phase signal may be added. In such a modification, the gain of the feedback loop may be adjusted (corrected) by the hybrid signal gain adjusting unit 28 as necessary.

  In addition, the scanning probe microscope of the present embodiment is similar to the third embodiment in that the amplitude display unit displays the amplitude signal output from the hybrid signal generation unit 70 and the phase signal output from the hybrid signal generation unit 70. It may be modified so as to include a phase display unit for displaying.

  The embodiments of the present invention have been described above with reference to the drawings. However, the present invention is not limited to these embodiments, and various modifications and changes can be made without departing from the scope of the present invention. Also good. Various modifications and changes described here may include implementations in which the above-described embodiments are appropriately combined. In addition, the present invention may include a device related to the configuration described in the embodiment and a method related to the operation described in the embodiment.

DESCRIPTION OF SYMBOLS 11 ... Probe, 12 ... Cantilever, 13 ... Holder, 14 ... Excitation part, 15 ... Displacement detection part, 16 ... Laser light source, 17 ... Divided detector, 18 ... Operation amplifier, 19 ... Sample, 20 ... Scanning part, 21 ... Z scanner, 22 ... XY scanner, 23 ... Z driver, 24 ... XY driver, 25 ... Controller, 26 ... Z control unit, 27 ... Host computer, 28 ... Hybrid signal gain adjustment unit, 30 ... Hybrid signal generation unit, 31 ... Amplitude information detection unit, 32 ... phase difference information detection unit, 33 ... phase adjustment unit, 34 ... signal generator, 35 ... calculation unit, 36 ... amplitude signal gain adjustment unit, 37 ... phase signal gain adjustment unit, 40 ... hybrid signal Generation unit 41 ... Phase difference information detection unit 42 ... Phase adjustment unit 50 ... Hybrid signal generation unit 51 ... Amplitude display unit 52 ... Phase display unit 60 ... Controller 61 ... Host compilation 70 ... hybrid signal generation unit, 71A ... amplitude signal amplification unit, 71B ... phase signal amplification unit, 72A ... amplitude signal amplification unit, 72B ... phase signal amplification unit, 73A ... amplitude signal amplification unit, 73B ... phase signal amplification Part, 74 ... selection part, 75 ... calculation part, 76 ... calculation part, 77 ... calculation part, 78 ... selection part.

Claims (27)

A cantilever with a probe at the free end;
A scanning unit that relatively moves the probe and the sample three-dimensionally;
An excitation unit that vibrates the cantilever based on an excitation signal;
A displacement detector that detects the displacement of the cantilever and outputs a displacement signal representing the displacement;
An amplitude information detector that detects amplitude information of the displacement signal and outputs an amplitude signal including the amplitude information, and a phase signal that detects phase difference information between the excitation signal and the displacement signal and includes the phase difference information A phase difference information detection unit that outputs a mixed signal generation unit that generates a mixed signal of the amplitude signal and the phase signal;
A control unit for controlling the distance between the probe and the sample based on the hybrid signal;
The scanning probe microscope is configured such that the hybrid signal generator is capable of adjusting a hybrid ratio between the amplitude signal and the phase signal.   The scanning probe microscope according to claim 1, wherein the hybrid signal generation unit is configured to independently adjust a gain of the amplitude signal and a gain of the phase signal.   The hybrid signal generation unit is output from the amplitude signal gain adjustment unit that can adjust the gain of the amplitude signal, the phase signal gain adjustment unit that can adjust the gain of the phase signal, and the amplitude signal gain adjustment unit. The scanning probe microscope according to claim 2, further comprising: an arithmetic unit that adds the amplitude signal and the phase signal output from the phase signal gain adjustment unit. The phase difference information detection unit includes a phase adjustment unit that gives a phase offset to a phase difference between the excitation signal and the displacement signal,
Wherein the excitation signal _{A 0 sinω} 0 t, the displacement signal and _{Asin (ω 0 t + φ 0} + φ), wherein, _{A 0} represents one of the aforementioned excitation signal amplitude, omega ₀ is the angular frequency of the excitation signal Number, t is time, A is the amplitude of the displacement signal, φ ₀ is the initial phase difference of the displacement signal that exists when the probe and the sample are not in contact, and φ is the difference between the probe and the sample A phase shift amount of the displacement signal generated due to contact, a gain of the amplitude signal gain adjustment unit is G _A , a gain of the phase signal gain adjustment unit is G _Φ , and the phase offset is ( −ψ),
The amplitude signal gain adjustment unit outputs G _A A as the amplitude signal, the phase signal gain adjustment unit outputs G _Φ Acos (φ ₀ + φ−ψ) as the phase signal, and the arithmetic unit The scanning probe microscope according to claim 3, which generates and outputs A (G _A + G _Φ cos (φ ₀ + φ−ψ)) as the hybrid signal. Wherein the phase offset (-ψ) is _{(π / 2-φ 0)} , i.e., ψ = φ ₀ -π / 2, therefore, the phase signal gain adjustment section stores, as the phase _signal, -G Φ Asinφ outputs, the computing unit, as the mixed _{signal, a (G a -G Φ sinφ} ) for outputting a scanning probe microscope according to claim 4. The amplitude information detection unit includes a first phase adjustment unit that gives a first phase offset to a phase difference between the excitation signal and the displacement signal,
The phase difference information detection unit includes a second phase adjustment unit that gives a second phase offset to the phase difference between the excitation signal and the displacement signal,
Wherein the excitation signal _{A 0 sinω} 0 t, the displacement signal and _{Asin (ω 0 t + φ 0} + φ), wherein, _{A 0} represents one of the aforementioned excitation signal amplitude, omega ₀ is the angular frequency of the excitation signal Number, t is time, A is the amplitude of the displacement signal, φ ₀ is the initial phase difference of the displacement signal that exists when the probe and the sample are not in contact, and φ is the difference between the probe and the sample A phase shift amount of the displacement signal generated due to contact, the gain of the amplitude signal gain adjustment unit is G _A , the gain of the phase signal gain adjustment unit is G _Φ , and the first phase When the offset is (−ψ ₁ ) and the second phase offset is (−ψ ₂ ),
The amplitude signal gain adjustment unit outputs G _A Acos (φ ₀ + φ−ψ ₁ ) as the amplitude signal, and the phase signal gain adjustment unit uses G _Φ Acos (φ ₀ + φ−ψ as the phase signal. outputs _2), the calculation unit, as the mixed _signal, and outputs the _{a (G a cos (φ 0} + φ-ψ 1) + G Φ cos (φ 0 + φ-ψ 2)), according to claim 3 Scanning probe microscope. The first phase offset (−ψ ₁ ) is (−φ ₀ ), that is, ψ ₁ = φ ₀ , and the second phase offset (−ψ ₂ ) is (π / 2−φ ₀ ). There, that is, _{ψ 2 = φ 0 -π / 2} , therefore, the amplitude signal gain adjusting section, as said amplitude signal, and outputs a G _a Acosφ, the phase signal gain adjustment section stores, as the phase signal, outputs _-G Φ Asinφ, the calculating unit, as the mixed _{signal, a (G a cosφ-G} Φ sinφ) for outputting a scanning probe microscope according to claim 6. The amplitude signal gain adjuster one gain G _A and the phase signal gain adjustment unit either gain G _[Phi of is 1, scanning probe microscope according to any one of claims 4 to claim 7.   The scanning probe microscope according to claim 1, wherein the hybrid signal generation unit is configured to adjust a gain of one of the amplitude signal and the phase signal.   The scanning probe microscope according to any one of claims 1 to 9, further comprising a hybrid signal gain adjustment unit capable of adjusting a gain of the hybrid signal.   11. The apparatus according to claim 1, further comprising at least one of a first information display unit that displays the amplitude information and a second information display unit that displays the phase difference information. Scanning probe microscope.   The scanning probe microscope according to claim 1, wherein the hybrid signal generation unit is configured to hybridize the amplitude signal and the phase signal at one of a plurality of preset hybrid ratios.   The hybrid signal generation unit amplifies both the amplitude signal and the phase signal with a plurality of preset first gains and a plurality of second gains, respectively, and amplifies with one of the plurality of first gains. The scanning probe microscope according to claim 12, wherein the scanning probe microscope is configured to add the signal and a phase signal amplified by one of the plurality of second gains. The hybrid signal generator is
A plurality of amplitude signal amplifying sections each amplifying the amplitude signal with a plurality of different first gains set in advance;
A plurality of phase signal amplifiers that respectively amplify the phase signals with a plurality of different second gains set in advance, wherein the plurality of amplitude signal amplifiers and the plurality of phase signal amplifiers are respectively It consists of multiple pairs,
A selection unit for selecting one of the amplitude signal amplification unit and one of the phase signal amplification unit constituting one of the plurality of pairs;
The amplitude signal output from one of the amplitude signal amplification units selected by the selection unit and the phase signal output from one of the phase signal amplification units selected by the selection unit are added. The scanning probe microscope according to claim 13, further comprising one arithmetic unit. The hybrid signal generator is
A plurality of amplitude signal amplifying sections each amplifying the amplitude signal with a plurality of different first gains set in advance;
A plurality of phase signal amplifiers that respectively amplify the phase signals with a plurality of different second gains set in advance, wherein the plurality of amplitude signal amplifiers and the plurality of phase signal amplifiers are respectively It consists of multiple pairs,
A plurality of arithmetic units that respectively add the amplitude signals output from the plurality of amplitude signal amplifiers constituting the plurality of pairs and the phase signals output from the plurality of phase signal amplifiers;
The scanning probe microscope according to claim 13, further comprising a selection unit that selects one of a plurality of signals output from the plurality of calculation units. The phase difference information detection unit includes a phase adjustment unit that gives a phase offset to a phase difference between the excitation signal and the displacement signal,
Wherein the excitation signal _{A 0 sinω} 0 t, the displacement signal and _{Asin (ω 0 t + φ 0} + φ), wherein, _{A 0} represents one of the aforementioned excitation signal amplitude, omega ₀ is the angular frequency of the excitation signal Number, t is time, A is the amplitude of the displacement signal, φ ₀ is the initial phase difference of the displacement signal that exists when the probe and the sample are not in contact, and φ is the difference between the probe and the sample a phase shift amount of the displacement signal generated due to contact with, also, the gain of the amplitude signal amplifying portion corresponding to the mixed signal outputted from said composite signal generator G _a, said composite signal generator When the gain of the phase signal amplifying unit corresponding to the hybrid signal output from is G _Φ and the phase offset is (−ψ),
The amplitude signal amplification unit outputs G _A A as the amplitude signal, the phase signal amplification unit outputs G _Φ Acos (φ ₀ + φ−ψ) as the phase signal, and the calculation unit includes: Examples mixed _{signal, a (G a + G Φ} cos (φ 0 + φ-ψ)) for outputting a scanning probe microscope according to claim 14 or claim 15. The phase offset (−ψ) is (π / 2−φ ₀ ), that is, ψ = φ ₀ −π / 2. Therefore, the amplitude signal amplification unit outputs G _A A as the amplitude signal. and, the phase signal amplifier, as the phase signal, and outputs the _-G Φ Asinφ, the calculating unit, as the mixed signal, and outputs the _{a (G a -G Φ sinφ)} , according to claim 16 Scanning probe microscope. The amplitude information detection unit includes a first phase adjustment unit that gives a first phase offset to a phase difference between the excitation signal and the displacement signal,
The phase difference information detection unit includes a second phase adjustment unit that gives a second phase offset to the phase difference between the excitation signal and the displacement signal,
Wherein the excitation signal _{A 0 sinω} 0 t, the displacement signal and _{Asin (ω 0 t + φ 0} + φ), wherein, _{A 0} represents one of the aforementioned excitation signal amplitude, omega ₀ is the angular frequency of the excitation signal Number, t is time, A is the amplitude of the displacement signal, φ ₀ is the initial phase difference of the displacement signal that exists when the probe and the sample are not in contact, and φ is the difference between the probe and the sample a phase shift amount of the displacement signal generated due to contact with, also, the gain of the amplitude signal amplifying portion corresponding to the mixed signal outputted from said composite signal generator G _a, said composite signal generator When the gain of the phase signal amplifying unit corresponding to the hybrid signal output from _Φ is G _Φ , the first phase offset is (−ψ ₁ ), and the second phase offset is (−ψ ₂ ),
The amplitude signal amplifying unit outputs G _A Acos (φ ₀ + φ−ψ ₁ ) as the amplitude signal, and the phase signal amplifying unit outputs G _Φ Acos (φ ₀ + φ−ψ ₂ ) as the phase signal. outputs, the computing unit, as the mixed _signal, and outputs the _{a (G a cos (φ 0} + φ-ψ 1) + G Φ cos (φ 0 + φ-ψ 2)), according to claim 14 or claim 15 A scanning probe microscope as described in 1. above. The first phase offset (−ψ ₁ ) is (−φ ₀ ), that is, ψ ₁ = φ ₀ , and the second phase offset (−ψ ₂ ) is (π / 2−φ ₀ ). There, that is, _{ψ 2 = φ 0 -π / 2} , therefore, the amplitude signal amplifier, as the amplitude _signal, and outputs a G a Acosφ, the phase signal amplifier, as the phase signal, -G _[Phi Asinfai outputs, the computing unit, as the mixed _{signal, a (G a cosφ-G} Φ sinφ) for outputting a scanning probe microscope according to claim 18. 20. The scanning according to claim 16, wherein when the hybrid ratio is G _A / G _Φ , the hybrid ratio includes a ratio smaller than 1 and a ratio larger than 1. Type probe microscope.   The hybrid signal generation unit amplifies one of the amplitude signal and the phase signal with a plurality of preset gains, and one of the amplitude signal and the phase signal amplified with one of the plurality of gains. The scanning probe microscope according to claim 12, configured to add the other of the amplitude signal and the phase signal.   The scanning probe microscope according to any one of claims 12 to 21, further comprising a hybrid signal gain adjustment unit capable of adjusting a gain of the hybrid signal.   23. The apparatus according to claim 12, further comprising at least one of a first information display unit that displays the amplitude information and a second information display unit that displays the phase difference information. Scanning probe microscope. A control method for a scanning probe microscope,
Oscillating a cantilever having a probe at a free end based on an excitation signal;
Scanning the probe along the surface of the sample;
Detecting a displacement of the cantilever and generating a displacement signal representing the displacement;
Generating an amplitude signal including amplitude information of the displacement signal;
Generating a phase signal including phase difference information between the excitation signal and the displacement signal;
Generating a hybrid signal of the amplitude signal and the phase signal;
Controlling the distance between the probe and the sample based on the hybrid signal;
The step of generating the hybrid signal is a control method in which a hybrid ratio between the amplitude signal and the phase signal can be adjusted.   The control method according to claim 24, further comprising at least one of a step of displaying the amplitude information and a step of displaying the phase difference information.   The control method according to claim 24, wherein the step of generating the hybrid signal hybridizes the amplitude signal and the phase signal at one of a plurality of preset hybrid ratios.   27. The control method according to claim 26, further comprising at least one of a step of displaying the amplitude information and a step of displaying the phase difference information.

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