JP3386641B2 - Non-contact electric measurement sensor and method of manufacturing the sensor - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a semiconductor wafer,
For a semiconductor in a broad sense including semiconductor thin films such as polysilicon and amorphous, a non-contact electrical measurement sensor used for non-contact electrical measurement in which non-contact measurement of electrical characteristics represented by a CV curve and the like is performed, and , A method of manufacturing the sensor.

[0002]

2. Description of the Related Art As one of methods for evaluating a semiconductor process having a MIS structure, an evaluation method by CV measurement is used. In the conventional CV measurement, it was necessary to form an electrode for electrical measurement on the surface of the oxide film on the semiconductor substrate, but the process of forming the electrode not only affects the electrical characteristics of the semiconductor itself. . There is a problem that the electrode formation itself takes time and effort.

Therefore, as shown in the conceptual diagram of FIG. 1, the applicant of the present invention does not form an electrode on the surface of a semiconductor and evaluates electrical characteristics such as CV measurement and Ct method without contact. Provided is a non-contact electrical measurement device that can be performed. In FIG. 1A, an oxide film 2 is formed on the front surface of a semiconductor wafer 1, and an electrode 3 is formed on the back surface. Above the oxide film 2, a measurement electrode 5 is held by an electrode holding unit 7 with a gap Ge therebetween.
The gap Ge between the oxide film 2 and the measuring electrode 3 is about 1 μm.
It is controlled by the electrode holding unit 7 as follows.

The capacitance Ct between the two electrodes 3, 5 is
As shown in FIG. 1B, the capacitance Cs of the semiconductor wafer 1, the capacitance Ci of the oxide film 2, and the capacitance Cg of the gap Ge are connected in series. The C-V curve is
It is the voltage dependence of the combined capacitance Cta of the capacitance Cs of the semiconductor wafer 1 and the capacitance Ci of the oxide film 2. The value of the gap Ge is accurately measured by the electrode holding unit 7, and the capacitance Cg of the gap is calculated based on the value of the gap Ge. The combined capacitance Ct is measured by the measuring unit 9, and the electrostatic capacitance Cg of the gap is subtracted from the combined capacitance Ct to obtain the capacitance Cta, whereby the CV curve as shown by the broken line in FIG. 1C is determined. It

Further, the applicant of the present invention has disclosed a sensor for non-contact electric measurement, which is the most suitable for the non-contact electric measuring device, as disclosed in Japanese Patent Laid-Open No.
The technology disclosed in Japanese Patent No. 335392 is provided. This non-contact electrical measurement sensor has a bottom view of FIG.
As is clear from the AA cross-sectional view shown in (b), a circular electrical measurement electrode S is formed in the center of the bottom surface of the cone glass CG.
P, three parallelism adjusting electrodes HP of the same shape provided at positions symmetrical to each other with respect to the electric measurement electrode SP, and a guard ring provided in an annular shape between these two types of electrodes. It has an electrode GP.

The non-contact electrical measurement sensor and the semiconductor to be measured are controlled to have a gap length of 1 μm or less by an optical system using a cone glass CG as an optical waveguide and detected by three parallelism adjusting electrodes HP. The parallelism is maintained so that the capacitances to be matched are the same. In addition, the three parallelism adjusting electrodes HP and the electric measuring electrode SP are capacitively cut off by the guard ring electrode GP which is always kept at a constant potential. Therefore, under this condition, if a desired electrical measuring device is connected to the electrical wiring that is conducted to the electrical measuring electrode SP, the electrical characteristics of the semiconductor to be measured can be measured in contact. .

[0007]

[Problems to be Solved by the Invention]

By the way, in the above-mentioned conventional non-contact electrical measurement sensor, it is necessary to provide an electrical wiring SPa for connecting the electrical measurement electrode SP and an external measuring device. The electrical wiring SPa is as follows. Problem occurred.

In this non-contact electrical measurement sensor, the electrical wiring SPa is attached along the surface of the cone glass CG, so that the electrical wiring SPa cuts out the guard ring electrode GP. For this reason, the electrostatic shield between the electric measurement electrode SP and the three parallelism adjusting electrodes HP could not be completely performed.

Further, the electric wiring SPa is shown in FIG.
As shown in, to reduce the parasitic capacitance as much as possible,
Although it is connected to the outside by the step portion and the inclined portion of μm, the electric field generated on the semiconductor surface as the measurement target by these portions disturbs the parallel electric field by the electrode SP for electric measurement, and not a little. Induced parasitic capacitance.
Moreover, when it is necessary to scan the voltage applied to the electrical measurement electrode SP, the influence of the nonlinear capacitance on the applied voltage contained in the parasitic capacitance cannot be removed by a simple subtraction process. However, the above parasitic capacitance could not be eliminated.

The present invention has been made to solve the above-mentioned problems, and makes the guard ring effect of the electrode for electric measurement sufficient and eliminates the electric parasitic capacitance generated in the electric wiring. The purpose is to measure the electrical characteristics of the semiconductor in a non-contact manner with higher accuracy.

[0012]

[Means for Solving the Problems and Their Actions / Effects] As means for solving the above problems, the following constitution is adopted.

The sensor for non-contact electrical measurement of the first invention comprises:
Almost parallel to the surface of the semiconductor with a gap
The arrangement electrical measurement electrode, a non-contact electrical measurement sensor for measuring the electrical characteristics of the semiconductor, the
1 surface and a second surface substantially parallel to the first surface
And holding the electric measurement electrode on the first surface and connecting the electric measurement electrode and an external measuring device with an electrode holding means formed of optical glass and serving as an optical waveguide.
Electrical wiring for connection, and
The wiring contacts the first surface of the electrode for electrical measurement.
Conducting a surface of the side, and the first table of the electrode holding means
It is characterized in that it is formed so as to penetrate from the surface to the second surface .

According to this non-contact electrical measurement sensor, from the side of the surface on which the electric wiring is in contact with the electrode holding means of the electrical measurement electrode, it will be extending through the electrode holding means formed of the optical glass, It is connected to a measuring device outside the non-contact electrical measurement sensor. Therefore, the electrical wiring of this, the electrical measurement electrode is to become the intervention, it is semiconductor and capacitively completely shielded between the semiconductor to be measured. Therefore, the measurement error due to the parasitic capacitance of the electric wiring can be surely eliminated. In addition, the above-mentioned electrode
Doesn't a step part for wire drawing be formed?
It is also possible to suppress the parasitic capacitance generated from this part.
It As a result, it is possible to measure the electrical characteristics of the semiconductor in a non-contact manner with higher accuracy.

In the sensor for non-contact electric measurement having the above structure
And is held on the first surface of the electrode holding means.
In addition, non-contact all around the electrode for electrical measurement
It may be configured to include a guard ring electrode surrounded by
preferable. According to this configuration, the area around the electrode for electrical measurement is
The electrostatic shield gar held by the electrode holding means
Interference with the drain electrode is avoided. Therefore, electrical measurements
It is possible to surely shield the electrodes for electrostatic discharge. Further, in addition to the electrostatic shield guard ring electrode, interference with other electrodes that need to be formed on the same plane as the electrical measurement electrode can be avoided. Therefore, there is an effect that the degree of freedom in designing these electrodes can be secured and the electrodes having a desired shape can be formed.

In the non-contact electrical measurement sensor having the above structure, the electrical wiring is electrically connected to the electrical measurement electrode.
Hollow-cylindrical conductivity whose conduction surface is a ring with a width W
The width W can be less than or equal to twice the predetermined gap D between the electrode for electrical measurement and the semiconductor . If this requirement is satisfied, even if the conducting part is formed by disturbing the flatness of the electrode for electrical measurement, the resulting disturbance of the parallel electric field between the electrode for electrical measurement and the semiconductor is negligible. Has a slight effect. The details of this principle will be described later. Further, according to the conductive surface of such ring-shaped, the contact area S (W × L) can be increased design, there is also an effect that smaller suppressing the contact resistance of the part.

Further, the electrical wiring is the electrical measurement battery.
The conductive surface of the conductive portion that is conductive with the pole has a width W and a length L (>
W) is a thin-line plate-shaped conductor, and the width W is
Of the predetermined gap D between the electrical measurement electrode and the semiconductor
It can be double or less. Do not satisfy this request
Shape, the conducting part disturbs the flatness of the electrode for electrical measurement.
Even if it is made, the resulting electrode and the semi-conducting electrode for electrical measurement
The disturbance of the parallel electric field with the body is negligible
effective. Moreover, according to such a thin conductive surface,
The contact area S (W × L) can be designed to be large, and the contact resistance at that portion can be suppressed small.

The method of manufacturing a non-contact electrical measurement sensor of the second invention, a test electrode, and the electrode holding means for holding a pre-Symbol test electrode, measured in the test electrode and the external
Electrical wiring for connecting to the
It is placed almost parallel to the surface with a certain gap.
In the method for manufacturing a non-contact electrical measurement sensor for measuring the electrical characteristics of the semiconductor with the electrical measurement electrode, a conductive electrical wiring is formed through the electrode holding means, and the electrical wiring is exposed. At least one surface of the electrode holding means is polished to a predetermined smoothness, and an electrode for electrical measurement is formed at a predetermined location on the one surface of the polished electrode holding means.

According to this structure, it is possible to manufacture the electric wiring by using various processing methods which are the same as the so-called through-hole manufacturing established as the method for manufacturing the electric circuit. Therefore, it becomes possible to apply the optimum through-hole manufacturing method when manufacturing electrical wiring of various shapes, arbitrary widths and lengths, and by applying the technically established through-hole manufacturing method. This has the effect of ensuring reliable conduction with the electrode for electrical measurement. Further, since the polishing step is performed after the step of forming the electric wiring, even if the smoothness of the surface is disturbed in the step of forming the electric wiring, this can be corrected and a surface having a desired smoothness can be formed. Here, the surface smoothness in the polishing step is preferably such that the surface undulation is suppressed to at least λ / 20 or less (where λ is the wavelength of light). If this condition is satisfied, there is an effect that 1 mm can be secured as the width of the electric measurement electrode of the non-contact electric measurement sensor.

The step of forming the conductive electric wiring in the manufacturing method having the above-mentioned structure is preferably performed by using the same or a low-hardness conductive material for the electrode holding means of the non-contact electrical measurement sensor. If a conductive substance having the same hardness or a low hardness as the electrode holding means is adopted in this step,
This has the effect of facilitating the subsequent polishing step. Further, the smaller the difference in hardness between the conductive substance and the electrode holding means, the easier it is to finish to a predetermined smoothness in the subsequent polishing step, and the flatness of the finally obtained electrode for electrical measurement can be improved. Can be higher. Even if the difference in hardness is large, the electric wiring portion having a low hardness is polished more greatly than the electrode holding means in the polishing process. Therefore, if the electrode for electric measurement is formed on one surface of the electrode holding means having the predetermined smoothness obtained by such a step, the contact portion where the electric wiring and the electrode for electric measurement are conducted can be formed into a concave shape. The influence of the contact portion on the parallel electric field can be suppressed to a negligible level. The influence of the concave contact portion on the parallel electric field will be described later in detail.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 3 is an explanatory diagram showing the configuration of an electric measuring device MD including a sensor as an embodiment of the present invention. The electric measuring device MD includes a measuring unit 20 that houses the semiconductor wafer 10, a light quantity measuring device 22, an impedance meter 24, a position control device 26, and a host controller 28. The light quantity measuring device 22, the impedance meter 24, and the position control device 26 are connected to a host controller 28, and the host controller 28 controls the entire measuring device and processes the obtained data. A personal computer, for example, is used as the host controller 28.

The measuring unit 20 includes a base 32 and a base 32.
The drive device 34 provided on the top, a mount 36 connected to the ball screw portion 34a of the drive device, and a sample table 38 placed on the mount 36 are provided. Sample table 3
Reference numeral 8 denotes a table on which the semiconductor wafer 10 as a test piece is placed, which is driven by a motor (not shown) to rotate in the XY plane.

A flange 42 is fixed by a bolt to the opening at the top of the housing 40 of the measuring section 20, and three piezoelectric actuator sections 44, 45, 46 using piezo elements are provided below the flange 42. There is. Further, a support plate 48 is provided below the piezoelectric actuator portions 44, 45, 46, and a sensor head 60 is fixed to the tip of a support cylinder 50 extending below the support plate 48.
The support plate 48 is connected to the flange 42 by a plurality of springs (not shown), and the piezoelectric actuator parts 44, 4
5, 46 are pushed up to the flange 42 side. The sensor head 60 includes a right-angle prism 62 for introducing laser light, and a translucent electrode forming portion 64 adhered to the bottom surface of the right-angle prism 62 with an optical adhesive.

A laser oscillator 70 such as a GaAlAs laser and a light receiving sensor 72 such as a photodiode are fixed to the support cylinder 50. The laser light emitted from the laser oscillator 70 passes through the rectangular prism 62 and the electrode forming portion 6
4 and is reflected on the bottom surface of the electrode forming portion 64 under the condition of total reflection of geometrical optics. Then, the reflected laser light is emitted from the rectangular prism 62 and received by the light receiving sensor 72.

When the electric measurement of the semiconductor wafer 10 is performed, the gap between the bottom surface of the sensor head 60 and the surface of the semiconductor wafer 10 is maintained at about 1 μm or less. An optical system including the laser oscillator 70, the sensor head 60, and the light receiving sensor 72 is an optical measuring system for precisely measuring this gap. This optical measurement system utilizes a tunneling phenomenon of laser light when the laser light oscillated from the laser oscillator 70 is reflected on the bottom surface of the sensor head 60 under a geometrical total reflection condition. The value of the gap is measured based on the light quantity measured by the light quantity measuring device 22.

The piezoelectric actuators 44, 45 and 46 are electrically connected to the position control device 26, the light receiving sensor 72 is connected to the light quantity measuring device 22 and electrodes formed on the bottom surface of the sensor head 60. The impedance meter 24 is connected to the metal sample table 38.
The impedance meter 24 includes the electrodes and the sample table 3
8 is a device for measuring the capacitance and conductance between

These light quantity measuring device 22 and position control device 26
And a method of adjusting the gap and parallelism executed by the host controller 28, a method of measuring the electrical characteristics of the semiconductor wafer 10 by the impedance meter 24 and the host controller 28, a method of processing the measurement results, and the like,
The details are described in Japanese Patent Application Laid-Open No. 4-32704 or Japanese Patent Application Laid-Open No. 5-335392, which is disclosed by the applicant of the present invention, and the details thereof are omitted here.

Next, the sensor head 60 employed in the measuring section 20 of this embodiment will be described in detail.

FIG. 4 is a perspective view of the electrode forming portion 64 of the sensor head 60 as seen obliquely from below, and further, the electric wiring 201a hidden inside and on the back surface thereof is drawn by dotted lines. The electrode forming portion 64 includes a cone glass 66 formed of optical glass and an electrode pattern 200 formed on the bottom surface 66 a of the cone glass 66. The electrode pattern 200 includes an electric measurement electrode 201, three parallelism adjusting electrodes 111, 112 and 113, and a guard ring electrode 120, and the electrodes 111 to 11 are included.
The wirings 111a and 1 connected to the wirings 3 and 120, respectively.
12a, 113a, 120a are included. These wirings extend from the bottom surface 66a of the cone glass 66 to the side sloped surface 66b.
Is formed across. In the present embodiment, the electric measurement electrode 201 is a circular electrode, and its diameter is 1.0 m.
mφ.

Three parallelism adjusting electrodes 111 to 113
Has a ring-like shape that is equally divided into three. The inner diameters of the rings of the parallelism adjusting electrodes 111 to 113 are 1.6 mmφ and the outer diameters are 2.4 mmφ. Also,
The distance between the electrodes 111 to 113 is 0.7 mm. The shape of each of these electrodes may be circular, but by forming a split ring shape as in this embodiment, there is an advantage that an electrode having a larger area can be formed in a smaller area. .

The parallelism adjusting electrodes 111 to 113 are
It is used when adjusting the parallelism between the bottom surface 66 a of the cone glass 66 and the surface of the semiconductor wafer 10. That is, if the expansion amount of the piezo elements of the piezoelectric actuators 44, 45, 46 is adjusted to adjust the inclination of the bottom surface 66a of the cone glass 66 and the capacitance values of the electrodes 111 to 113 are made equal to each other, the cone The bottom surface 66a of the glass 66 and the surface of the semiconductor wafer 10 can be made parallel to each other.

The guard ring electrode 120 is a ring-shaped electrode provided between the electrical measurement electrode 201 and the parallelism adjusting electrodes 111 to 113, and its inner diameter is 1.2 mm.
φ, the outer diameter is 1.4 mmφ. Guard ring electrode 12
0 is maintained at a predetermined potential (for example, ground potential) and 4
It has a role of preventing an interaction between the two electrodes 201 and 111 to 113.

The electrodes 201, 111 to 113, 1
The gap between the 20 is set to 0.1 mm, and the width of the wirings 111a to 113a on the bottom surface 66a is set to 0.1 mm.

The cone glass 66 is obtained by polishing a disk-shaped glass and cutting the side surface into a tapered shape. Since the bottom surface 66a of the cone glass 66 is parallel to the surface 66c,
The electrode pattern 200 formed on the bottom surface 66a can be easily formed by photolithography. Further, at a predetermined position on the bottom surface of the electrode forming portion 64, a reflecting portion (not shown) that reflects the laser light emitted from the laser oscillator 70 under the condition of geometrical optical total reflection is formed, and the reflected laser light is at a right angle. The light is emitted from the prism 62 and received by the light receiving sensor 72. With these optical measurement systems, the gap between the electric measurement electrode 201 and the semiconductor wafer 10 is maintained at about 1 μm or less.

On the other hand, the electrical wiring 2 of the electrode 201 for electrical measurement
01a is other wiring 111a-113a, 120a
The surface 66 facing the bottom surface 66a of the cone glass 66 is electrically connected to the back surface of the electric measurement electrode 201 unlike
It is composed of a hollow-cylindrical conductor that is embedded to penetrate to c and a strip-shaped conductor that is electrically connected to the hollow-cylindrical conductor that appears on the surface 66c and reaches the annular side surface 66d of the cone glass 66. There is. The hollow cylindrical conductor has an outer diameter of 300 μm and a difference between the outer diameter and the inner diameter, that is, a wiring width W of 0.8 μm.

Since the electric wiring 201a is formed in this manner, the electric measurement electrode 201 facing the semiconductor wafer 10 is formed.
In addition, since there is no step portion for drawing out the wiring, it is possible to completely eliminate the non-linear parasitic capacitance to the measurement voltage applied to the electric measurement electrode 201, and only show the wiring capacitance having a simple constant value. effective.

As is clear from the principle described below, the wiring width W of the electric wiring 201a is 0.8 μm.
Therefore, even if the smoothness of the electrical measurement electrode 201 is reduced due to the electrical wiring 201a that is electrically connected to the back surface of the electrical measurement electrode 201, the electrical measurement accuracy is not reduced. That is, in order to maintain the electrical measurement accuracy, it is necessary to generate a parallel electric field on the semiconductor wafer 10, which is an ideal electric field that can be easily analyzed.

FIG. 5 shows the electric field generated between the semiconductor wafer 10 and the electrode for electric measurement 201 when the smoothness of the electrode for electric measurement 201 in which the electric wiring 201a is conducted is disturbed. It is an explanatory view represented by. As can be understood from the figure, the mutual relationship between the gap D between the electric measurement electrode 201 and the semiconductor wafer 10 and the width W of the electric wiring 201a is important for the condition that the electric field on the semiconductor wafer 10 becomes a parallel electric field. Become. As described above, the gap D in this embodiment is about 1 μm or less.

It is difficult to accurately manufacture the concave portion 201b generated in the electric measurement electrode 201 due to the electric wiring 201a so as to match its shape with a specific shape. In other words, the width W of the electric wiring 201a must be designed under the condition that the electric field on the semiconductor wafer 10 keeps a parallel electric field, no matter what the concave portion 201b is formed in the electric measurement electrode 201. I have to. Therefore, it is necessary to set conditions under which the concave portions 201b most adversely affect the electric field on the semiconductor wafer 10, that is, conditions under which electric lines of force are concentrated and distributed at both ends of the width W of the electric wiring 201a.

In order to satisfy the above conditions, the same potential surface (equipotential surface) when there are two point charges separated by a width W is defined by Moon and Spencer ("Electric field calculation method" by Pretz, Asakura Shoten (1974)). (See) to find the mapping function of the following equation (1).

Z = (W / 2) (e ^a +1) ^1/2 where a = X + iY (1)

The real part of this complex function is a function group representing the equipotential surface. Therefore, FIG. 6 specifically plots only the necessary two quadrants of this function group. As is clear from FIG. 6, even if there are two point charges q and q ′ across the width W, the equipotential surface at a point W / 2 or more away from the point charges q and q ′ is substantially horizontal. Has become. That is,
The electric field at a point separated by W / 2 or more from the point charges q and q'is orthogonal to this equipotential surface, and therefore is substantially perpendicular to the plane of width W.

Therefore, as shown in FIG.
The condition for the electric field on 0 to be a parallel electric field without being disturbed by the point charges having the width W is that the distance D between the semiconductor wafer 10 and the electrode for electrical measurement 201 is 1/2 or more of the width W. It turns out to be sufficient. In the present embodiment in which the distance D is about 1 μm or less, the electrical wiring 201a having the width W of 0.8 μm completely satisfies this condition.

Further, the electric wiring 201a of this embodiment is electrically connected to the electric measurement electrode 201 in the shape of a hollow cylinder having an outer diameter of 300 μm, which is a locus longer than 0.8 μm having a width W. Therefore, while satisfying the constraint imposed on the width W described above, it is possible to conduct electricity to the electrical measurement electrode 201 over a large area of about 238 μm ² and suppress the contact resistance thereof to be small.

Further, since the electrical wiring 201a of the electrode for electric measurement 201, which is preferably located in the center of the electrode pattern 200, is provided through the cone glass 66, the guard ring electrode provided on the outer periphery of the electrode for electric measurement 201 is provided. It becomes possible to make 120 a closed curved surface electrode which is completely closed. By providing the guard ring electrode 120 having such a closed curved surface, the parallelism adjusting electrodes 111 to 113 are formed.
Since the capacitance value of the electrode 201 for electric measurement can be measured by completely shutting off the influence from, the measurement accuracy of electric measurement can be improved.

The wirings 111a to 113a and 12 drawn out to the outermost peripheral portion of the cone glass 66 as described above.
0a and 201a are connected to external lead wires at the ends of the side slopes 66b of the cone glass 66. The wiring is connected by wire bonding or a curable silver paste, and the connecting portion may rise by several hundreds of μm. The wiring is connected at a position separated upward from the bottom surface 66a of the cone glass 66 so that the bulge of the connection portion is not sandwiched between the bottom surface 66a of the cone glass 66 and the surface of the semiconductor wafer 10. This is because. At the time of electrical measurement, the gap between the bottom surface 66a and the surface of the semiconductor wafer 10 is set to about 1 μm or less. The problem of contact with the wafer 10 arises. In this embodiment, since the truncated cone cone glass 66 is used, the bottom surface 6 is formed in this way.
The wiring on the electrode forming portion 64 can be connected to an external lead wire at a position separated from 6a.

As described above in detail, the sensor head 60 having excellent effects is manufactured in the following process sequence.

First, an optical glass such as BK7 used as a material for the cone glass 66 is polished into a shape as shown in the perspective view of FIG. The bottom surface of this cone glass 66 becomes the surface forming the above-mentioned electrode. Next, cone glass 6
A ring-shaped through hole is formed at the center of 6, and platinum to be the electric wiring 201a is buried in the through hole by the same process as the through hole fabrication. Then, the bottom surface 66a of the cone glass 66 forming the electrode pattern 200 is polished and finished to have a required smoothness, and then the electrode pattern 200 having the above-mentioned shape is formed by a technique such as etching or vapor deposition.

According to such a manufacturing method, no matter what shape, width W, and length the electric wiring 201a is manufactured, it is possible to apply the through-hole manufacturing method most suitable for the manufacturing. By applying the technically established through-hole manufacturing method, it is possible to manufacture the sensor head 60 having a long life which is resistant to disconnection and the like.

Further, since the polishing step is performed after the step of forming the electric wiring 201a, even if the smoothness of the bottom surface 66a is disturbed in the manufacturing step of the electric wiring 201a, this is corrected to form a surface having a desired smoothness. can do. Further, since the hardness of the electric wiring 201a made of platinum is lower than that of the cone glass 66 made of optical glass, the electric wiring 201a exposed on the bottom surface 66a in the above polishing step is polished much more than the cone glass 66. The concave portion 201b as shown in FIG. 5 can be formed.

Although the sensor head 60 of the embodiment has been described above, the shape and the like of the electric wiring 201a are not limited to those in the above embodiment, and can be optimally designed according to the overall configuration of the electric measuring device MD. . That is, the electric wiring 201a may have any shape as long as the width W satisfies the condition that the width W is equal to or less than twice the distance D between the electric measurement electrode 201 and the semiconductor wafer 10 to be measured. As shown in the electric wiring 201aa in FIG. 7, it may be straight. Further, as shown in FIG. 8, the electric wiring 201ab penetrating the cone glass 66 may be routed to the side sloped surface 66b, and the connection point with the external measuring instrument may be changed. Further, if the problem of contact resistance is ignored, the electric wiring 201a may be configured by a simple wire conductor.

Further, the shape of the electrode pattern 200 other than the electric wiring 201a can be designed arbitrarily. In FIG. 9, the electric wiring 201ac has a hollow cylindrical shape as in the detailed embodiment, and the electric wiring 201ac is
This is an example in which the electrode for electrical measurement 201x that is in conduction with is formed in a ring shape. If the electrical measurement electrode 201x is formed in a ring shape in this way, a laser light reflection surface 66e can be provided at the center of the bottom surface 66a of the cone glass 66, and the gap measurement with the semiconductor wafer 10 by the optical measurement system can be performed. The effect is simple.

Further, the electrode pattern 20 is not limited to the electric wiring 201a, which is the wiring of the electric measurement electrode 201, and other electrode patterns 20.
It is also possible to form a wiring of 0 through the cone glass 66. FIG. 10 shows other electrode patterns, ie, parallelism adjusting electrodes 111b to 113b and a guard ring electrode 12.
This is an example in which the wirings 111c to 113c and 120c of 0b are formed in through holes like the electrical wiring 201ad of the electrode 201y for electric measurement. According to this embodiment, the bottom surface 6
There is an effect that the electrode pattern 200 formed on 6a becomes the minimum necessary and the occupied area thereof becomes the minimum, and the electrode patterns are completely independent, so that the degree of freedom in designing the electrode shape is increased.

The present invention is not limited to the embodiments described above, but can be implemented in various forms without departing from the scope of the invention, and is not limited to a sensor head for a CV measuring device. Generally, it can be applied to a sensor head used in an apparatus for measuring the electrical characteristics between a measuring electrode and a semiconductor substrate in a non-contact manner.

Other electrical measurements include, for example, the evaluation of the characteristics near the semiconductor surface by examining the time dependence of the combined capacitance Cta by the Zerubst method. Further, if the conductance is measured by the impedance meter 24, it is possible to evaluate the interface state and the like at the interface between the semiconductor wafer and the oxide film. Furthermore, if CV measurement is performed in the state where no oxide film is formed on the semiconductor wafer during each process such as the cleaning process of the semiconductor wafer, the thermal oxidation process, and the heat treatment for stabilizing the oxide film, each of these processes is performed. The quality of processing can be determined.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an outline of an electric measurement method for a semiconductor.

FIG. 2 is a structural explanatory view of a conventional sensor for non-contact electrical measurement.

FIG. 3 is a diagram showing a configuration of an electric measuring device as a first embodiment of the present invention.

FIG. 4 is a bottom perspective view of a sensor head of the electric measuring device.

FIG. 5 is an explanatory diagram of an electric field generated on a semiconductor wafer by the sensor head.

FIG. 6 is an explanatory diagram of an equipotential surface generated by two point charges.

FIG. 7 is a bottom perspective view of the sensor head of the second embodiment.

FIG. 8 is a bottom perspective view of the sensor head of the third embodiment.

FIG. 9 is a bottom perspective view of the sensor head of the fourth embodiment.

FIG. 10 is a bottom perspective view of the sensor head of the fifth embodiment.

[Explanation of symbols]

10 ... Semiconductor wafer 20 ... Measuring unit 22 ... Light quantity measuring device 24 ... Impedance meter 26 ... Position control device 28 ... Host controller 32 ... Base 34 ... Drive device 34a ... Ball screw part 36 ... Stand 38 ... Sample table 40 ... Housing 42 ... Flange 44 ... Piezoelectric actuator 48 ... Support plate 50 ... Support tube 60 ... Sensor head 62 ... Right angle prism 64 ... Electrode forming part 66 ... Corn glass 66a ... bottom 66b ... Side slope 66c ... surface 66d ... annular side surface 66e ... Reflective surface 70 ... Laser oscillator 72 ... Light receiving sensor 111 to 113 ... Electrodes for adjusting parallelism 111a to 113a ... Wiring 120 ... Guard ring electrode 200 ... Electrode pattern 201 ... Electrode for electrical measurement 201a ... electrical wiring 201aa ... electrical wiring 201ab ... electrical wiring 201ac ... electrical wiring 201ad ... electrical wiring

Continuation of the front page (56) References JP-A 64-82541 (JP, A) JP-A 1-199172 (JP, A) Actual development 2-118274 (JP, U) (58) Fields investigated (Int .Cl. ⁷ , DB name) G01R 1/06-1/073 G01R 31/28-31/3193

Claims (6)

(57) [Claims] 1. A predetermined gap is formed between the semiconductor surface and the semiconductor surface.
The electrodes for electrical measurement placed almost parallel to each other
A contactless electrical measurement sensor for measuring electrical characteristics of a semiconductor , comprising: a first surface; and a second surface substantially parallel to the first surface.
And an electrode holding means for holding the electric measurement electrode on the first surface and forming an optical waveguide formed of optical glass, the electric measurement electrode and an external measuring device. For connecting with
Electrical wiring is provided, the electrical wiring is electrically connected to a surface of the electrical measurement electrode that is in contact with the first surface, and the electrical wiring is provided in front of the first surface of the electrode holding means.
A sensor for non-contact electrical measurement, which is formed so as to penetrate to the second surface . 2. A sensor for non-contact electrical measurement according to claim 1.
And when held on the first surface of the electrode holding means:
However, the entire circumference of the electrical measurement electrode is removed without contact.
Non-contact electrical measurement sensor with a surrounding guard ring electrode
Sa. 3. A hollow circle in which the conductive surface of a conductive portion of the electrical wiring, which is in electrical communication with the electrical measurement electrode, is an annular shape having a width W.
A conductor of the tubular, wherein the width W is, non-contact electrical measurement sensor according to claim 1, wherein a is less than twice the predetermined gap D between the semiconductor and the test electrode . 4. The electric wiring has a conductive surface of a conductive portion, which has a width W and a length L (> W), which is conductive with the electrode for electrical measurement .
3. A non-contact plate-shaped conductor having a thin wire shape, wherein the width W is equal to or less than twice a predetermined gap D between the electrode for electrical measurement and the semiconductor. Electrical measurement sensor. 5. A test electrode, and the electrode holding means for holding a pre-Symbol test electrode, and a <br/> electrical wiring for connecting the test electrode and the external measuring instrument And a predetermined gap from the surface of the semiconductor.
The previous SL for electric measurement electrodes arranged parallel to pot, in the manufacturing method of non-contact electrical measurement sensor for measuring the electrical characteristics of the semiconductor to form an electrical wiring of the conductive through said electrode holding means A surface of the electrode holding means where the electrical wiring is exposed is polished to a predetermined smoothness, and an electrode for electrical measurement is formed at a predetermined location on the one surface of the polished electrode holding means. Manufacturing method of sensor for contact electric measurement. 6. The method according to claim 5, wherein the step of forming the electric wiring is performed with respect to the electrode holding means of the sensor for non-contact electrical measurement using the same or a conductive material having a low hardness. Manufacturing method of sensor for non-contact electric measurement.