JP3173554B2 - Measurement method of high frequency characteristics of dielectric thin film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention measures the high frequency characteristics of a dielectric thin film formed on a semiconductor substrate, which is applied to the manufacture of a semiconductor device having a dielectric thin film formed on a semiconductor substrate. The present invention relates to a method for measuring high-frequency characteristics of a dielectric thin film.

[0002]

2. Description of the Related Art Conventionally, when measuring a high frequency characteristic H of a dielectric thin film F formed on a semiconductor substrate B, as shown in FIG. The lower electrode layer for measurement ELM formed and (b) the shape extending from the lower electrode layer for measurement ELM on the substrate BB to the dielectric thin film formed on the semiconductor substrate B and the material. The upper electrode for measurement formed so as to extend on the dielectric thin film for measurement FM similarly formed from above and (c) the dielectric thin film for measurement FM so as to face the lower electrode layer for measurement ELM. A measurement element DM having a layer EUM is formed, and a high-frequency characteristic HM between the measurement lower electrode layer ELM and the measurement upper electrode layer EUM of the measurement element DM is measured. Using the measurement result of the high frequency characteristic HM, Frequency characteristic measuring method of the dielectric thin film say has been proposed.

In this case, the high frequency characteristic H of the measuring element DM
The measurement of M is performed by measuring the lower electrode layer ELM of the measuring element DM.
And admittance Y _A between the upper electrode layers EUM for measurement
Measurement.

The method of using the measurement result of the high frequency characteristic HM of the measuring element DM is described in the following.
If the measurement, a measurement of the admittance Y _A viewed between measurements lower electrode layer of the measuring device DM ELM and measuring the upper electrode layer EUM, from the admittance Y _A, the frequency f
Of the capacitance C between the lower electrode layer ELM for measurement and the upper electrode layer EUM for measurement with respect to
There determined Toka whether exhibiting any value by the value of the value or any range as the frequency f throat, the measured admittance Y from the _A of the measuring dielectric thin film FM dielectric loss tan [delta, its dielectric loss tan [delta what values of and has a obtains the relative dielectric constant ε of the measuring dielectric thin FM from the measured admittance Y _a, can determine knowledge, such as whether the relative dielectric constant ε exhibits what value Can be used.

[0005] The above is a method of measuring high-frequency characteristics of a dielectric thin film that has been conventionally proposed.

According to such a conventional method for measuring high-frequency characteristics of a dielectric thin film, the measuring element DM can be easily formed by a method conventionally used for manufacturing a semiconductor device. The high-frequency characteristics H of the dielectric thin film F formed on the substrate B can be easily measured.

[0007]

In the conventional method for measuring the high-frequency characteristics of a dielectric thin film shown in FIG. 4, the measurement of the high-frequency characteristics HM of the measuring device DM is performed by measuring the high-frequency characteristics HM of the measuring device DM. If the ELM and measurement of admittance Y _a viewed between measurements for the top electrode layer EUM, the measuring device D
Admittance Y _A of M is, generally, not represented in the equivalent admittance circuit consisting of only admittance Y _C of the capacitance C between the measuring lower electrode layer ELM and measured for the top electrode layer EUM for the frequency f, as shown in FIG. 5 Admittance Y _C of capacitance C between lower electrode layer ELM for measurement and upper electrode layer EUM for measurement, and parasitic admittance Y in series therewith
_S and parasitic admittance Y _{P in} parallel with admittance Y _C
Because represented by an equivalent admittance circuit with bets, measuring lower electrode layer ELM and the lower electrode layer ELM and measuring upper electrode for measurement for measuring the upper electrode layer EUM Demi was admittance Y _M from a frequency f of the measurement element DM Layer EUM
If the relationship between the capacitances C is determined, the lower electrode layer ELM for measurement and the upper electrode layer EU for measurement with respect to the frequency f are obtained.
Assuming that the capacitance C between M is represented by an equivalent admittance circuit in which the measuring element DM includes only the admittance Y _{C of the} capacitance C, for example, as shown by a line a in FIG.
Although obtained as a constant value at a value of 0 GHz or less, as shown in a line b of FIG.
It is obtained by exhibiting a value that increases as the frequency f increases in a value in the range of GHz to 50 GHz.

For this reason, in the conventional method for measuring high-frequency characteristics of a dielectric thin film shown in FIG. 4, it is possible to accurately measure the high-frequency characteristics H of a dielectric thin film F formed on a semiconductor substrate B. There was a drawback that it was not possible.

Therefore, the present invention proposes a novel method for measuring high-frequency characteristics of a dielectric thin film which does not have the above-mentioned disadvantages.

[0010]

The method for measuring the high-frequency characteristics of a dielectric thin film according to the present invention measures the high-frequency characteristics of a dielectric thin film formed on a semiconductor substrate. As in the case of the high-frequency characteristic measurement method,
(A) a lower electrode layer for measurement formed on a substrate corresponding to the semiconductor substrate; and (b) a lower electrode layer for measurement formed on the substrate, extending on the lower electrode layer for measurement. And (c) formed on the dielectric thin film for measurement so as to extend so as to face the lower electrode layer for measurement. Forming a measurement element having a measurement upper electrode layer,
Then, the high-frequency characteristics of the measurement element between the measurement lower electrode layer and the measurement upper electrode layer are measured, and the measurement results of the high-frequency characteristics of the measurement element are used.

However, the method for measuring the high-frequency characteristics of a dielectric thin film according to the present invention is the same as the method for measuring the high-frequency characteristics of a dielectric thin film described above, except that (i) (a) is formed on the substrate on the substrate. A first correction lower electrode layer formed similarly to the measurement lower electrode layer, and (b) the same as the measurement dielectric thin film extending on the measurement lower electrode layer on the substrate. A first correction dielectric thin film formed in the same manner as the measurement dielectric thin film formed on the substrate by extending on the first correction lower electrode layer; On the first correction dielectric thin film, the measurement upper electrode layer formed on the measurement dielectric thin film and the measurement upper electrode layer are extended so as to face the measurement lower electrode layer. Make sure that it does not extend so as to face the first correction lower electrode layer. Except that a first correcting element having a first correcting upper electrode layer formed in the same manner as above is formed, and the first correcting lower electrode layer of the first correcting element is formed. And measuring the high-frequency characteristics between the first correction upper electrode layers in the same manner as in the measurement of the high-frequency characteristics of the measurement element, and (ii) (a) forming on the substrate and on the substrate; A second lower electrode layer for correction formed in the same manner as the lower electrode layer for measurement, and (b) the dielectric for measurement extending on the lower electrode layer for measurement on the substrate. Like the thin film, the second correcting dielectric thin film formed on the substrate and extending on the second correcting lower electrode layer and formed in the same manner as the measuring dielectric thin film formed on the substrate ( c) on the second dielectric thin film for correction, on the dielectric thin film for measurement The upper electrode layer for measurement, and the second upper electrode layer for correction is not extended so as to be opposed to the lower electrode layer for measurement. A second compensating element having a similarly formed second compensating upper electrode layer except that it is coupled to the second compensating lower electrode layer; and The second element of the correction element
The high-frequency characteristics between the lower electrode layer for correction and the second upper electrode layer for correction are measured in the same manner as in the measurement of the high-frequency characteristics of the measurement element, and (iii) the high-frequency characteristics of the measurement element are measured. The measurement result is corrected by the measurement result of the high-frequency characteristic of the first correction element and the measurement result of the high-frequency characteristic of the second correction element, and the corrected measurement result of the high-frequency characteristic of the measurement element is obtained. This is used as a result of measuring the high-frequency characteristics of the measuring element.

[0012]

Next, an embodiment of a method for measuring high-frequency characteristics of a dielectric thin film according to the present invention will be described with reference to FIG.

In FIG. 1, parts corresponding to those in FIG. 4 are denoted by the same reference numerals.

In the embodiment of the method for measuring the high frequency characteristics of a dielectric thin film according to the present invention shown in FIG. 1, the high frequency characteristics H of a dielectric thin film F formed on a semiconductor substrate B are measured. As in the case of the method of measuring the high frequency characteristics of a dielectric thin film, (a) a lower electrode layer EL for measurement formed on a substrate BB corresponding to the semiconductor substrate B and (b) a lower electrode layer for measurement on the substrate BB. Extending on the lower electrode layer ELM, the dielectric thin film F is formed on the semiconductor thin film B in the same manner as the dielectric thin film F is formed on the semiconductor substrate B and (c) on the dielectric thin film for measurement FM. Forming a measuring element DM having a measuring upper electrode layer EUM extending so as to face the measuring lower electrode layer ELM, and forming the measuring lower electrode layer ELM and the measuring element DM of the measuring element DM. -Frequency characteristics H viewed between upper electrode layers EUM It was measured, using the measurement results of the frequency characteristics HM the measuring device DM.

In this case, the high frequency characteristic H of the measuring element DM
Measurement of M is of the conventional 4 as in the case of the dielectric thin film of the high-frequency characteristics measuring method, the admittance Y _A viewed between measurements lower electrode layer of the measuring device DM ELM and measuring the upper electrode layer EUM It can be a measurement.

The method of using the measurement result of the high-frequency characteristic HM of the measuring element DM is the same as that of the conventional method of measuring the high-frequency characteristic of the dielectric thin film shown in FIG. the measurement, when the measurement of the admittance Y _a viewed between measurements lower electrode layer ELM measuring element DM and measured for the upper electrode layer EUM, in the case of high frequency characteristics measuring method of the conventional dielectric thin film shown in FIG. 4 analogously, in its admittance Y _a corrected admittance Y _a as described later in '
The relationship between the capacitance C between the lower electrode layer ELM for measurement and the upper electrode layer EUM for measurement with respect to the frequency f is obtained, and the obtained capacitance C is determined at what value of the frequency f or in what range of the value of the frequency f. From the corrected admittance Y _A , the dielectric loss tan δ of the dielectric thin film FM for measurement is determined, and the value of the dielectric loss tan δ is determined, and the corrected admittance Y _A ′
Is used to determine the relative dielectric constant ε of the dielectric thin film FM for measurement and to know what value the relative dielectric constant ε exhibits.

In the embodiment of the method for measuring the high-frequency characteristics of a dielectric thin film according to the present invention shown in FIG. 1, the method for measuring the high-frequency characteristics of a dielectric thin film described above includes the steps of: The first lower electrode layer ELM of the measuring element DM formed on the substrate BB is formed on the same substrate BB used for the measurement on the same material as the first lower electrode layer ELM. Similarly, on the correction lower electrode layer ELC1 and (b) on the substrate BB, from the shape of the measurement dielectric thin film FM extending on the measurement lower electrode layer ELM of the measurement element MM, the first correction Extending to the lower electrode layer ELC1, the first compensating dielectric film FM is formed in the same manner as the material and the shape of the measuring dielectric thin film FM of the measuring device DM formed on the substrate BB. Body thin film FC1 and (c) for its first correction On-collecting thin film FC1, and measuring the dielectric thin film FM measurement upper electrode layer is formed on the EUM of the measuring device DM, it lower electrode layer EL measurement
Except that it does not extend opposite to the first lower electrode layer for correction ELC1 so as to extend opposite to M.
The first formed similarly from the material and the shape
And a first correction element DC1 having the upper correction electrode layer EUC1.
The high-frequency characteristics HC1 between the first first correction lower electrode layer ELC1 and the first correction upper electrode layer EUC1 are measured in the same manner as in the measurement of the high-frequency characteristics HM of the measuring element DM.

In this case, the measurement of the high frequency characteristic HC1 of the first correction element C1 is based on the measurement of the high frequency characteristic HM of the measurement element DM described above. when as a measurement of the admittance Y _a viewed between electrode layers EUM, first correction element DC
It may be a measure of the admittance Y _B viewed between 1 of the first correction for the lower electrode layer ELC1 and first correction upper electrode layer EUC1.

(Ii) (a) On the substrate BB, the lower correction layer ELM formed on the substrate BB and the second correction formed similarly from the material and the shape. The lower electrode layer ELC2 for measurement and (b) the second lower electrode for correction similarly to the dielectric thin film FM for measurement extending on the lower electrode layer ELM for measurement of the element for measurement DM on the substrate BB. The second correcting dielectric film extending from the electrode layer ELC2 to the measuring dielectric thin film FM of the measuring element DM formed on the substrate BB and formed similarly from the material and the shape. The body thin film FC2 and (c) the measuring dielectric thin film FM of the measuring element DM on the second correcting dielectric thin film FC2.
The upper measurement electrode layer EUM formed thereon and the second lower electrode layer for correction should not extend so as to extend opposite to the lower electrode layer for measurement ELM. And a second upper correction electrode layer EUC2 similarly formed from the material and the shape except that it is connected to the second lower electrode layer for correction ELC2. The correction element DC2 is formed, and the high-frequency characteristics HC2 viewed between the second correction lower electrode layer ELC2 and the second correction upper electrode layer EUC2 of the second correction element DC2 are measured. The measurement is performed in the same manner as the measurement of the high frequency characteristics HM.

In this case, the measurement of the high-frequency characteristic HC2 of the second correction element C2 is based on the measurement of the high-frequency characteristic HM of the measurement element DM described above, and the measurement of the lower electrode layer ELM and the upper measurement layer of the measurement element DM. when as a measurement of the admittance Y _a viewed between electrode layers EUM, the second correction element DC
It may be a measure of the admittance Y _D viewed between 2 of the second correction lower electrode layer ELC2 and second correction for the upper electrode layer EUC2.

(Iii) The measurement result of the high frequency characteristic HM of the measuring element DM is compared with the measurement result of the high frequency characteristic HC1 of the first correcting element DC1 and the second correcting element DC2.
The measurement result of the high frequency characteristic HM of the measurement element DM is used as the measurement result of the high frequency characteristic HM of the measurement element DM.

In this case, the high frequency characteristic H of the measuring element DM
The measurement result of M is corrected by the high-frequency characteristic H of the measuring element DM.
Measurement of M and the measurement of the admittance Y _A viewed between measurements lower electrode layer ELM measuring element DM as described above and measured for the upper electrode layer EUM, also first correction element DC1
Of the high frequency characteristic HC1 of the first correction element DC1 between the first correction lower electrode layer ELC1 and the first correction upper electrode layer EUC1 as described above.
_B , and the measurement of the high frequency characteristic HC2 of the second correction element DC2 is performed as described above.
If the measurement of the admittance Y _D viewed between the second correcting lower electrode layer ELC2 and second correction for the upper electrode layer EUC2 of C2, the admittance Y _A using admittance Y _B and Y _C admittance Y _A ' To be corrected.

Further, manner of using the measurement results of the frequency characteristics HM of the corrected measurement element DM is the measurement results of the frequency characteristics HM of the measuring device DM, corrects the admittance Y _A described above in admittance Y _A ' when the objects, from the admittance Y _a ', measuring device D with respect to the frequency f
M lower electrode layer ELM and upper electrode layer EU for measurement
Obtained relation capacitance C between M, the the obtained capacitance C Toka whether exhibiting any value by the value of the value or any range as the frequency f throat, measuring dielectric from admittance Y _A ' seeking a dielectric loss tanδ of the thin film FM, whether the dielectric loss tanδ are exhibited any value, the dielectric constant of the measuring dielectric thin FM from admittance Y _a epsilon
Is obtained, and it can be used so that the value of the relative permittivity ε can be known.

The above is an embodiment of the method for measuring high-frequency characteristics of a dielectric thin film according to the present invention.

According to the method for measuring the high-frequency characteristics of a dielectric thin film according to the present invention, the measuring element DM is connected to the same as the conventional method for measuring the high-frequency characteristics of a dielectric thin film shown in FIG.
It can be easily formed by a method conventionally used for manufacturing a semiconductor device, and the first and second correction elements DC1 and DC2 can be easily formed at the same time as the measurement element DM. So you can
The high frequency characteristics H of the dielectric thin film F formed on the semiconductor substrate B can be easily measured.

In the method for measuring the high-frequency characteristics of the dielectric thin film according to the present invention shown in FIG. 1, the measurement of the high-frequency characteristics HM of the measuring device DM is performed by the same method as described above. and the measurement of the admittance Y _a viewed between measurements for the top electrode layer EUM, also for the first correction of the first correction element DC1 measured frequency characteristics HC1 of the first correction element DC1 as described above Lower electrode layer ELC
The admittance Y _B is measured between the first and first correction upper electrode layers EUC1, and the second correction element DC2
Of the high frequency characteristic HC2 of the second correction element DC2 as described above between the second correction lower electrode layer ELC2 and the second correction upper electrode layer EUC2.
_When measuring _D , the admittance Y of the measuring element DM
_A is generally the lower electrode layer EL for measurement with respect to the frequency f.
It is not represented by an equivalent admittance circuit consisting of only the admittance Y _C of the capacitance C between M and the upper electrode layer EUM for measurement.
Even if it is represented by an equivalent admittance circuit having an admittance Y _C of the capacitance C between the LM and the measurement upper electrode layer EUM, a parasitic admittance Y _{S in} series with the admittance Y _S, and a parasitic admittance Y _{P in} parallel with the admittance Y _C , Admittance Y viewed between the first correction lower electrode layer ELC1 and the first correction upper electrode layer EUC1 of the first correction element C1.
_B is generally the admittance Y _{C of} FIG. 2A shown in FIG. 2B.
Are represented by an open equivalent admittance circuit, and the second correction lower electrode layer E of the second correction element DC2 is
Since the admittance Y _D viewed between the LC2 and the second upper electrode layer for correction EUC2 is generally represented by an equivalent admittance circuit in which the admittance YC in FIG. 2A shown in FIG. 2C is short-circuited, the admittance circuit Y _C is used. , Y _C = {(Y _A −Y _B ) (Y _C −Y _B ) / (Y _C −Y _A )} Y ₀
= G + iωC (Y0 is a constant), and its admittance YC
Is used to determine the relationship of the capacitance C between the lower electrode layer ELM for measurement and the upper electrode layer EUM for measurement with respect to the frequency f.
FIG. 3 is obtained when the capacitance C between the LM and the measurement upper electrode layer EUM is represented by an equivalent admittance circuit composed of only the admittance Y _{C of the} capacitance C.
As shown in a line a in FIG. 6, the frequency f is obtained as a constant value at a value of 50 GHz or less.

As described above, in the method of measuring high-frequency characteristics of a dielectric thin film according to the present invention shown in FIG. 1, the high-frequency characteristics H of a dielectric thin film F formed on a semiconductor substrate B are compared with those of the prior art shown in FIG. It can be measured more accurately than the method of measuring the high frequency characteristics of a dielectric thin film.

In the above, only one embodiment of the method for measuring the high-frequency characteristics of a dielectric thin film according to the present invention has been described, and various modifications and changes can be made without departing from the spirit of the present invention. There will be.

[Brief description of the drawings]

FIG. 1 is a schematic plan view (FIG. 1A) showing a measuring element and first and second correcting elements for explaining a high-frequency characteristic measuring method of a dielectric thin film according to the present invention, and bb thereof. It is sectional drawing on a line (FIG. 1B).

FIG. 2 is a diagram showing an equivalent circuit of a measurement element and first and second correction elements for explaining a method of measuring high-frequency characteristics of a dielectric thin film according to the present invention shown in FIG. 1;

FIG. 3 is a diagram illustrating the relationship between the capacitance (C) and the frequency f obtained from the measurement result of the high-frequency characteristics of the measuring element, for explaining the method of measuring the high-frequency characteristics of the dielectric thin film according to the present invention shown in FIG. .

4A and 4B are a schematic plan view (FIG. 4A) showing a measuring element and a cross-sectional view taken along the line bb (FIG. 4B) for explaining a conventional method for measuring high-frequency characteristics of a dielectric thin film.

FIG. 5 is a diagram showing an equivalent circuit of a measuring element for explaining the conventional method for measuring high-frequency characteristics of a dielectric thin film shown in FIG.

FIG. 6 is a diagram illustrating the relationship between the capacitance (C) and the frequency f obtained from the measurement result of the high-frequency characteristics of the measuring element, for explaining the conventional method for measuring the high-frequency characteristics of the dielectric thin film shown in FIG.

[Explanation of symbols]

 B Semiconductor substrate BB, BC substrate DC1, DC2 Correction element DM measurement element EUM measurement upper electrode layer ELM measurement lower electrode layer EUC1, EUC2 Correction upper electrode layer ELC1, ELC2 Correction lower electrode layer F Dielectric thin film FC1 , FC2 Dielectric thin film for correction Dielectric thin film for FM measurement

Continuation of the front page (56) References JP-A-5-34388 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01R 27/26 H01L 21/66

Claims (1)

(57) [Claims] 1. A high-frequency characteristic of a dielectric thin film formed on a semiconductor substrate is measured by: (a) a lower electrode layer for measurement formed on a substrate corresponding to the semiconductor substrate; A dielectric thin film for measurement formed on the substrate and extending on the lower electrode layer for measurement and formed in the same manner as the dielectric thin film formed on the semiconductor substrate; On the body thin film, to form a measurement element having a measurement upper electrode layer formed to extend so as to face the measurement lower electrode layer,
In the method for measuring high-frequency characteristics between the lower electrode layer for measurement and the upper electrode layer for measurement of the measurement element, and using the measurement result of the high-frequency characteristics of the measurement element, (A) a first correction lower electrode layer formed on the substrate in the same manner as the measurement lower electrode layer formed on the substrate; and (b) a measurement lower electrode layer formed on the substrate. Like the measurement dielectric thin film extending on the lower electrode layer, extending on the first correction lower electrode layer in the same manner as the measurement dielectric thin film formed on the substrate. A first correction dielectric thin film formed, and (c) an upper electrode layer for measurement formed on the dielectric thin film for measurement, on the first dielectric thin film for correction, and The above-described first electrode extends so as to face the lower electrode layer for measurement. A first correction element having a first correction upper electrode layer similarly formed except that the first correction element does not extend so as to face the first correction lower electrode layer; The high-frequency characteristics of the first correction lower electrode layer and the first correction upper electrode layer of the first correction element are measured in the same manner as in the measurement of the high-frequency characteristic of the measurement element. ii) (a) A second electrode formed on the substrate in the same manner as the lower electrode layer for measurement formed on the substrate.
And (b) extending on the second correction lower electrode layer on the substrate in the same manner as the measurement dielectric thin film extending on the measurement lower electrode layer. A second dielectric thin film for correction formed in the same manner as the dielectric thin film for measurement formed on the substrate, and (c) a second dielectric thin film for correction.
On the correction dielectric thin film, the upper electrode layer for measurement formed on the dielectric thin film for measurement, and the first electrode layer as described above so that it extends facing the lower electrode layer for measurement. 2
And the second correction upper electrode layer, which is formed in the same manner, except that it does not extend opposite to the correction lower electrode layer and is connected to the second correction lower electrode layer. Is formed, and the high-frequency characteristics of the second correction element viewed between the second correction lower electrode layer and the second correction upper electrode layer are compared with those of the measurement element. The measurement is performed in the same manner as the measurement of the high-frequency characteristics. (Iii) The measurement result of the high-frequency characteristics of the measuring element is
The measurement result of the high-frequency characteristic of the first correction element and the measurement result of the high-frequency characteristic of the second correction element are corrected, and the corrected measurement result of the high-frequency characteristic of the measurement element is used for the measurement. A method for measuring high-frequency characteristics of a dielectric thin film, which is used as a result of measuring the high-frequency characteristics of an element.