JP5639034B2 - Film thickness measuring method and film thickness measuring apparatus, semiconductor integrated circuit manufacturing method, control program, and readable storage medium - Google Patents

Description

  The present invention relates to a method and apparatus for measuring a film thickness of a conductive laminated film in which an electroless gold plating or the like is laminated on an electrode in an electronic device manufacturing process or the like, and is laminated on an electrode of an electronic component using the film thickness measuring apparatus. A method for manufacturing a semiconductor integrated circuit for measuring a film thickness of a conductive laminated film to manufacture a non-defective product managed semiconductor integrated circuit, and a processing procedure for causing a computer to execute each step of the film thickness measuring method are described. The present invention relates to a control program and a computer-readable readable storage medium storing the control program.

  Conventionally, an electrode of an electronic component such as a semiconductor device forms a conductive film by various methods, but various characteristics such as conductivity, corrosion resistance, wear resistance, and bonding characteristics are required depending on the purpose of use. Manufacturing cost reduction is necessary. In order to realize these, an electrode of an electronic component is often laminated with a plurality of conductive films. For example, the electrode characteristics can be remarkably improved by applying a thin gold plating to the base metal. In the manufacturing process of an electronic component having an electrode in which different conductive films are laminated, it is important to measure and manage the laminated film thickness in order to achieve high quality.

  There are various methods for measuring the film thickness of the conductive film, and methods using light, electron beams, and X-rays have been realized. For example, Patent Document 1 discloses a method for converting the film thickness from the intensity of fluorescent X-rays. Patent Document 2 discloses a method for converting the intensity into a film thickness of characteristic X-rays obtained by irradiating an object to be measured with an electron beam.

  In Patent Document 1, while scanning a primary X-ray beam across a thin sample, the X-ray beam is applied to the sample by comparing the fluorescence X-ray integrated intensity from the material of this sample with the calculated value of the integrated intensity. The position reached is quickly determined. Thereby, even if the moving speed of the primary X-ray beam is increased as compared with the prior art, it can be reliably determined whether or not the X-ray beam has crossed the sample. Therefore, the measurement position search of the sample can be performed quickly and reliably without being affected by the measurement start position.

  In Patent Document 2, in a film thickness measurement method, a characteristic X-ray generated from a substance constituting a substrate by scanning the film deposited on the substrate with an electron beam probe and passing through the film and reaching the substrate. The strength is measured, and the thickness of the thin film is determined from the relationship between the thickness of the thin film determined in advance and the characteristic X-ray intensity.

Japanese Patent Laid-Open No. 6-102032 JP-A-2-266208

  However, in the conventional film thickness measurement methods disclosed in Patent Documents 1 and 2, an X-ray or electron beam source is required, and it is necessary to isolate the source so as not to affect the human body. Is expensive and expensive, and it takes about 5 minutes for one measurement due to the accumulated time of X-rays. It is difficult to adopt for quality control in mass production processes, and is inexpensive. A film thickness measurement method capable of high-speed measurement is desirable.

  The present invention solves the above-described conventional problems, and a film thickness measuring method and a film thickness measuring apparatus capable of measuring the film thickness of a conductive laminated film such as an electrode of an electronic component at high speed with a simple and inexpensive apparatus. , A method of manufacturing a semiconductor integrated circuit for manufacturing a non-defectively managed semiconductor integrated circuit by measuring the film thickness of a thin film such as an electrode on a semiconductor substrate of an electronic component using the film thickness measuring apparatus, It is an object of the present invention to provide a control program in which a processing procedure for causing a computer to execute each step is described, and a computer-readable readable storage medium in which the control program is stored.

In the film thickness measuring method of the present invention, in the laminated film in which the first conductive layer having two different resistivities and the second conductive layer thereon are laminated, the film thickness measuring means steps the film thickness of the laminated film. And measuring with a stylus or using a laser beam, and measuring the surface resistance value of the surface of the laminated film, the second conductive layer having a small resistivity from the measured film thickness of the laminated film and the surface resistance value thickness have a film thickness measuring step of obtaining by calculation, on the first conductive layer is smaller second conductive layer having the resistivity higher resistivity, and the film thickness in the resistivity of at least 10-fold Is at least 10 times, thereby achieving the above object.

  Preferably, in the film thickness measurement step in the film thickness measurement method of the present invention, the measurement control means controls the measurement unit to determine the film thickness of the laminated film of the first conductive layer and the second conductive layer. A measurement control step for measuring and measuring the surface resistance value, and a calculation means for calculating the film thickness of the second conductive layer by a predetermined calculation formula based on the film thickness of the laminated film and the surface resistance value Process.

  Further preferably, in the measurement control step in the film thickness measuring method of the present invention, the layer having a high resistivity is at least 10 times the resistivity and the film thickness is at least 10 times that of the layer having a low resistivity. Is measured.

  Further preferably, in the film thickness measurement method of the present invention, the determination means determines whether the film thickness of the second conductive layer is within a predetermined range, and the film thickness of the second conductive layer is within the predetermined range. If it is within the range, it is determined that the product is a non-defective product, and if the film thickness of the second conductive layer is not within the predetermined range, it is further provided with a determination step of determining that the product is defective.

  Further preferably, the measurement of the surface resistance value on the surface of the laminated film in the film thickness measuring method of the present invention uses a four-end needle method.

  Further preferably, the measurement accuracy of the film thickness of the laminated film in the film thickness measuring method of the present invention is at most 1/10 of the film thickness of the laminated film.

  Further preferably, in the film thickness measuring method of the present invention, the first conductive layer is a Ni layer, the second conductive layer is an Au layer, the first conductive layer is a Ni layer, and the second conductive layer is Ag. The layer or the first conductive layer is a titanium layer, and the second conductive layer is a Cu layer.

  Further preferably, in the film thickness measurement method of the present invention, the film thickness of the laminated film of the first conductive layer and the second conductive layer is an electrode height on the semiconductor substrate.

  Further preferably, when sheet resistance is used as the surface resistance value in the film thickness measurement method of the present invention, the resistivity ρ1, ρ2 of the first conductive layer and the second conductive layer and the thickness of the laminated film As T, the predetermined calculation formula is Equation 4.

  Furthermore, preferably, when the sheet resistance value is used as the surface resistance value in the film thickness measurement method of the present invention, the resistivity ρ0 and the film thickness t0 of the underlying conductive layer are used, and the first conductive layer laminated on the underlying conductive layer is used. As the resistivity ρ1, ρ2 of the layer and the second conductive layer and the film thickness T of the laminated film, the predetermined calculation formula is Equation 6.

  Further preferably, when a conductor resistance value is used as the surface resistance value in the film thickness measuring method of the present invention, the resistivity ρ1, ρ2 of the first conductive layer and the second conductive layer and the thickness of the laminated film As T, the predetermined calculation formula is Equation 9.

  Further, preferably, when a conductor resistance value is used as the surface resistance value in the film thickness measurement method of the present invention, the resistivity ρ0 and the film thickness t0 of the underlying conductive layer are used, and the first conductive layer laminated on the underlying conductive layer is used. As the resistivity ρ1, ρ2 of the layer and the second conductive layer and the film thickness T of the laminated film, the predetermined calculation formula is Expression 11.

The film thickness measuring apparatus of the present invention measures the film thickness of the laminated film with a stylus as a step in a laminated film in which a first conductive layer having two different resistivities and a second conductive layer thereon are laminated. Or using a laser beam to measure the surface resistance value of the surface of the laminated film, and calculate the film thickness of the laminated film and the thickness of the second conductive layer having a low resistivity from the surface resistance value. have a film thickness measuring means for obtaining a result, the first conductive layer is smaller second conductive layer having the resistivity higher resistivity, a the resistivity of at least 10 times and a thickness of at least 10-fold There is something, and the above purpose is achieved.

  Preferably, the film thickness measuring means in the film thickness measuring apparatus of the present invention controls the measurement unit to measure the film thickness of the laminated film of the first conductive layer and the second conductive layer, and the surface. Measurement control means for measuring the resistance value, and calculation means for obtaining the film thickness of the second conductive layer by a predetermined calculation formula based on the film thickness of the laminated film and the surface resistance value.

  Further preferably, the measurement control means in the film thickness measuring apparatus of the present invention is characterized in that the layer having a high resistivity has a resistivity of at least 10 times and a film thickness of at least 10 times that of the layer having a low resistivity. Is measured.

  Furthermore, preferably, it is determined whether the film thickness of the second conductive layer in the film thickness measuring apparatus of the present invention is within a predetermined range, and if the film thickness of the second conductive layer is within the predetermined range, Judgment means is further provided for judging that the second conductive layer is not defective when the thickness of the second conductive layer is not within the predetermined range.

  Further preferably, the measurement of the surface resistance value on the surface of the laminated film in the film thickness measuring device of the present invention uses a four-end needle method.

  Further preferably, the measurement accuracy of the film thickness of the laminated film in the film thickness measuring apparatus of the present invention is at most 1/10 of the film thickness of the laminated film.

  Further preferably, in the film thickness measuring apparatus of the present invention, the first conductive layer is a Ni layer, the second conductive layer is an Au layer, the first conductive layer is a Ni layer, and the second conductive layer is Ag. The layer or the first conductive layer is a titanium layer, and the second conductive layer is a Cu layer.

  Still preferably, in a film thickness measuring apparatus according to the present invention, the film thickness of the laminated film of the first conductive layer and the second conductive layer is an electrode height on the semiconductor substrate.

  Furthermore, preferably, when using a sheet resistance value as the surface resistance value in the film thickness measuring device of the present invention, the resistivity ρ1, ρ2 of the first conductive layer and the second conductive layer and the thickness of the laminated film As T, the predetermined calculation formula is Equation 4.

  Further, preferably, when the sheet resistance value is used as the surface resistance value in the film thickness measuring apparatus of the present invention, the resistivity ρ0 and the film thickness t0 of the underlying conductive layer are used, and the first conductive layer laminated on the underlying conductive layer is used. As the resistivity ρ1, ρ2 of the layer and the second conductive layer and the film thickness T of the laminated film, the predetermined calculation formula is Equation 6.

  Further, preferably, when a conductor resistance value is used as the surface resistance value in the film thickness measuring apparatus of the present invention, the resistivity ρ1, ρ2 of the first conductive layer and the second conductive layer and the thickness of the laminated film As T, the predetermined calculation formula is Equation 9.

  Further, preferably, when the conductor resistance value is used as the surface resistance value in the film thickness measuring apparatus of the present invention, the resistivity ρ0 and the film thickness t0 of the underlying conductive layer are used, and the first conductive layer laminated on the underlying conductive layer is used. As the resistivity ρ1 and ρ2 of the layer and the second conductive layer and the film thickness T of the laminated film, the predetermined calculation formula is Equation 11.

  The method for manufacturing a semiconductor integrated circuit according to the present invention is the method for manufacturing the second conductive layer in which the metal pad layer of the semiconductor substrate on which the semiconductor integrated circuit is formed is plated using the film thickness measuring apparatus according to the present invention. The film thickness is measured and non-defective products are managed to manufacture a semiconductor integrated circuit on the semiconductor substrate, thereby achieving the above object.

  The control program according to the present invention describes a processing procedure for causing a computer to execute each step of the film thickness measuring method according to the present invention, thereby achieving the above object.

  The readable storage medium of the present invention is a computer-readable storage medium storing the control program of the present invention, thereby achieving the above object.

  With the above configuration, the operation of the present invention will be described below.

  In the present invention, in a laminated film in which a first conductive layer having two different resistivities and a second conductive layer thereon are laminated, the film thickness measuring means includes the film thickness of the laminated film and the surface of the laminated film. A film thickness measurement step of measuring the surface resistance value and calculating the film thickness of the laminated film and the thickness of the second conductive layer having a low resistivity from the surface resistance value.

  Accordingly, the thickness of the conductive laminated film such as the electrode of the electronic component can be easily and easily obtained by calculating the thickness of the second conductive layer having a low resistivity from the measured film thickness and surface resistance value. It becomes possible to measure at high speed with an inexpensive apparatus.

  As described above, according to the present invention, since the thickness of the second conductive layer having a low resistivity is obtained by calculation from the measured thickness and surface resistance value of the laminated film, the conductive laminated film such as an electrode of an electronic component can be obtained. The film thickness can be measured at high speed with a simple and inexpensive apparatus.

It is a perspective view which shows schematic structure of the laminated conductive layer formed on the insulating film in order to demonstrate the film thickness measuring method in Embodiment 1 of this invention. It is a longitudinal cross-sectional view which shows the outline of the film thickness measurement of the 2nd conductive layer in the laminated film of the laminated | stacked 1st conductive layer / 2nd conductive layer of FIG. It is a longitudinal cross-sectional view which shows the outline of the film thickness measuring method of the 2nd conductive layer in the laminated film of the laminated | stacked 1st conductive layer / 2nd conductive layer in case there exists a base conductive layer. It is a longitudinal cross-sectional view which shows schematic structure of the film thickness measuring method of a specific laminated conductive layer. It is a figure which shows the thickness dependency of the laminated film of a resistance value by an actual value and a theoretical value, respectively. It is a figure which shows the Au film thickness dependence of resistance value with an actual measurement value and a theoretical value, respectively. It is a block diagram which shows the schematic structural example of the film thickness measuring apparatus which concerns on Embodiment 1 of this invention. It is a flowchart for demonstrating operation | movement of the thickness measuring apparatus of FIG.

  Below, the film thickness measuring method and film thickness measuring apparatus of the present invention, and the semiconductor integrated circuit managed by non-defective products by measuring the film thickness of the conductive laminated film laminated on the electrode of the electronic component using the film thickness measuring apparatus. Of a semiconductor integrated circuit for manufacturing a semiconductor integrated circuit, a control program describing a processing procedure for causing a computer to execute each step of the film thickness measuring method, and implementation of a computer-readable storage medium storing the control program Embodiment 1 will be described in detail with reference to the drawings. In addition, each thickness, length, etc. of the structural member in each figure are not limited to the structure to illustrate from a viewpoint on drawing preparation.

(Embodiment 1)
FIG. 1 is a perspective view showing a schematic configuration of a laminated conductive layer formed on an insulating film in order to explain a film thickness measuring method in Embodiment 1 of the present invention.

  In FIG. 1, the film thickness measuring method of the first embodiment is a method of forming electrodes on a semiconductor substrate comprising conductive layers 2 and 3 (laminated films, for example, Ni layer and Au layer thereon) laminated on an insulating film 1. On the other hand, the step of measuring the thickness (electrode height) of the conductive layers 2 and 3 by a known method, such as when measuring the step with a stylus or using laser light, and the surface resistance of the electrode by the four-end needle method A conductive film which is an upper film of an electrode composed of conductive layers 2 and 3 which are laminated vertically from the film thickness (electrode height) and surface resistance value of the laminated film obtained from the two steps. The film thickness of the layer 3 is calculated. The relationship between the laminated two conductive layers 2 and 3 is that the layer having a high resistivity (conductive layer 2) has a resistivity of 10 times or more and the thickness of the layer having a low resistivity (conductive layer 3). By being 10 times or more, the measurement accuracy by calculation can be ensured.

  FIG. 2 is a longitudinal sectional view showing an outline of the measurement of the film thickness of the second conductive layer 3 in the laminated film of the first conductive layer 2 / second conductive layer 3 laminated in FIG.

  As shown in FIG. 2, two conductive layers 2 and 3 are formed on the insulating film 1, and the predetermined thickness is determined from the flowing constant current using the thickness of the laminated film (conductive layers 2 and 3) and the four-end needle method. When the surface resistance is measured by measuring the voltage between the positions, the film thickness of the conductive layer 3 having a low resistivity can be obtained by calculation by the following method.

  In the case of a continuous surface, the sheet resistance value is used as the surface resistance value, and when the cross-sectional area is known with a finite size, the conductor resistance value is used as the surface resistance value. The method of calculating the film thickness of the conductive layer 3 having a small resistivity differs between the sheet resistance value and the conductor resistance value.

  First, when the sheet resistance value is used as the surface resistance value, the resistivity and film thickness of the conductive layers 2 and 3 to be laminated are as follows.

First conductive layer 2... Resistivity (volume resistivity): ρ1 Film thickness: t1
Second conductive layer 3... Resistivity (volume resistivity): ρ2 Film thickness: t2
It is assumed that the first conductive layer 2 and the second conductive layer 3 formed thereon have the following relationship (Equation 1). The first conductive layer 2 is, for example, a Ni layer, and the second conductive layer 3 thereon is, for example, an Au layer.

また、第１の導電層２および第２の導電層３の積層膜の膜厚をＴ、表面抵抗値をρｓとすると、表面抵抗値ρｓと各積層膜（導電層２、３）の関係は次式（数２）で表される。

Further, when the film thickness of the laminated film of the first conductive layer 2 and the second conductive layer 3 is T and the surface resistance value is ρs, the relationship between the surface resistance value ρs and each laminated film (conductive layers 2 and 3) is It is represented by the following formula (Formula 2).

したがって、求める値である導電率の小さい積層膜（導電層３）の膜厚ｔ２は、次式（数３）で与えられる。

Therefore, the film thickness t2 of the laminated film (conductive layer 3) having a low conductivity, which is a required value, is given by the following equation (Equation 3).

導電層２、３の積層膜の膜厚（電極高さ）をＴとし、

から、

とすると、導電層３の膜厚ｔ２は、次の式（数４）

The film thickness (electrode height) of the laminated film of the conductive layers 2 and 3 is T,

From

Then, the film thickness t2 of the conductive layer 3 is expressed by the following equation (Equation 4).

から求めることができる。

Can be obtained from

  That is, when the sheet resistance value is used as the surface resistance value, the film thickness of the conductive layer 3 is calculated by using the above equation (Equation 4) as the resistivity ρ1, ρ2 and film thickness T of the conductive layers 2 and 3 to be laminated. It can be obtained by calculation.

  FIG. 3 is a longitudinal sectional view showing an outline of a method for measuring the thickness of the second conductive layer 3 in the laminated film of the first conductive layer 2 / the second conductive layer 3 when there is a base conductive layer. is there.

As shown in FIG. 3, when the base conductive layer 4 is formed on the insulating film 1 and the conductive layers 2 and 3 are similarly stacked on the base conductive layer 4,
Underlying conductive layer 4 ... Resistivity: ρ0 Film thickness: t0
Then, similarly, the following equation (Equation 5) holds.

したがって、第２の導電層３の層厚ｔ２は次式（数６）で近似できる。

Therefore, the layer thickness t2 of the second conductive layer 3 can be approximated by the following equation (Equation 6).

なお、下地導電層４の表面抵抗を表すρ０／ｔ０は予め測定しておくことができ、図１の場合と同様の方法で第２の導電層３の層厚ｔ２を計算で求めることができる。

Note that ρ0 / t0 representing the surface resistance of the underlying conductive layer 4 can be measured in advance, and the layer thickness t2 of the second conductive layer 3 can be calculated by the same method as in FIG. .

  That is, when the sheet resistance value is used as the surface resistance value, the resistivity ρ0 and the film thickness t0 of the base conductive layer 4 are set, and the resistivity ρ1, ρ2 and the film thickness of the conductive layers 2 and 3 stacked on the base conductive layer 4 are used. As T, the film thickness of the conductive layer 3 can be obtained by calculation using (Formula 6) as the above formula.

  Next, when the conductor resistance value is used as the surface resistance value, the resistivity and film thickness of the conductive layers 2 and 3 to be laminated are as follows.

First conductive layer 2... Resistivity: ρ1 Film thickness: t1
Second conductive layer 3 Resistivity: ρ2 Film thickness: t2
The length L of the conductive layer and the width of the conductive layer are W.

  It is assumed that the first conductive layer 2 and the second conductive layer 3 have the following relationship (Equation 7).

また、積層膜（導電層２、３）の膜厚（電極高さ）をＴ、積層膜（導電層２、３）の抵抗値をＲとすると、Ｒと各積層膜（導電層２、３）の関係は次式（数８）で表される。

Further, assuming that the film thickness (electrode height) of the laminated film (conductive layers 2 and 3) is T and the resistance value of the laminated film (conductive layers 2 and 3) is R, R and each laminated film (conductive layers 2 and 3). ) Is expressed by the following equation (Equation 8).

したがって、同様に、第２の導電層３の層厚ｔ２は次式（数９）で表される。

Therefore, similarly, the layer thickness t2 of the second conductive layer 3 is expressed by the following equation (Equation 9).

即ち、表面抵抗値として導体抵抗値を用いる場合に、積層する導電層２，３の抵抗率ρ１、ρ２および膜厚Ｔとして上記計算式として（数９）を用いて導電層３の膜厚を計算により求めることができる。

That is, when the conductor resistance value is used as the surface resistance value, the film thickness of the conductive layer 3 is calculated by using the above equation (Equation 9) as the resistivity ρ1, ρ2 and film thickness T of the conductive layers 2 and 3 to be laminated. It can be obtained by calculation.

Further, when the base conductive layer 4 is formed on the insulating film 1 and the conductive layers 2 and 3 are similarly stacked on the base conductive layer 4,
Underlying conductive layer 4 ... Resistivity: ρ0 Film thickness: t0
Then, similarly, the following equation (Equation 10) holds.

したがって、第２の導電層３の層厚ｔ２は次式（数１１）で近似できる。

Therefore, the layer thickness t2 of the second conductive layer 3 can be approximated by the following equation (Equation 11).

となる。

It becomes.

  That is, when the conductor resistance value is used as the surface resistance value, the resistivity ρ0 and the film thickness t0 of the base conductive layer 4 are set, and the resistivity ρ1, ρ2 and the film thickness of the conductive layers 2 and 3 stacked on the base conductive layer 4 are used. As T, the film thickness of the conductive layer 3 can be obtained by calculation using (Equation 11) as the above formula.

  FIG. 4 is a longitudinal sectional view showing a schematic configuration of a specific method for measuring the thickness of a laminated conductive layer. FIG. 4 shows an outline of a method for measuring the layer thickness of the second conductive layer 3 in the stacked film of the first conductive layer 2 / second conductive layer 3 stacked.

As shown in FIG. 4, first, an aluminum film 12 having a thickness of 1.5 μm and a volume resistivity of 2.75 × 10 ⁻⁸ Ωm is formed on a smooth insulating substrate 11 by sputtering. Furthermore, the aluminum electrode 12 (underlying conductive layer 4) is formed as an island pattern having a width of 0.8 mm and a length of 2.2 mm by using a photolithography technique and a metal etching technique.

Next, electroless nickel plating is performed by a known double zincate method, and three types of 5 μm, 10 μm, and 15 μm in thickness are formed as the Ni—P coating 13 (first conductive layer 2) having a volume resistivity of 50 × 10 ⁻⁸ Ωm. A sample is prepared. Next, substitution gold plating is performed on each of these samples to form an Au film 14 (second conductive layer 3) having a thickness of 0.3 μm and a volume resistivity of 2.2 × 10 ⁻⁸ Ωm.

  On the sample of the Ni-P film 13 having a thickness of 10 μm, an Au film 14 having an Au film thickness of 0.1 μm and 0.5 μm is laminated.

  The surface of the Au coating 14 is irradiated with the laser beam L from the laser generator 15, the laser beam L reflected from the surface of the Au coating 14 is received by the laser displacement meter 16, and the Ni-P coating 13 / The film thickness (electrode height) of the Au coating 14 is measured, and then the surface resistance is measured by a four-end needle method.

  FIG. 5 shows the measured value and the theoretical value of the dependence of the resistance value on the thickness of the laminated film, and FIG. 6 shows the dependence of the resistance value on the Au film thickness. The actually measured value is in good agreement with the theoretical value, and the film thickness of the Au film can be obtained from the thickness of the laminated film and the resistance value.

  For example, when the thickness of the Ni-P film 13 is 10 μm and the thickness of the Au film 14 of the displacement gold plating is 0.3 μm, the actually measured resistance value is 0.031Ω. The theoretical value at this time is represented by the following formula (formula 12) using the formula (formula 10) described above.

また、体積抵抗率が１０：１となる金属の組み合わせの一例としては、チタン４２．７×１０^−８Ωｍと銅１．６８×１０^−８Ωｍが挙げられる。

An example of a combination of metals with a volume resistivity of 10: 1 is titanium 42.7 × 10 ⁻⁸ Ωm and copper 1.68 × 10 ⁻⁸ Ωm.

  Here, the film thickness measuring apparatus 20 using the film thickness measuring method of the first embodiment will be described in detail.

  FIG. 7 is a block diagram illustrating a schematic configuration example of the film thickness measuring apparatus 20 according to the first embodiment of the present invention.

  In FIG. 7, the film thickness measuring device 20 of the first embodiment is configured by a computer system, and according to various input commands, an operation unit 21 such as a keyboard, a mouse, and a screen input device that enables various input commands. A display unit 22 that can display various images such as an initial screen, a selection guide screen, and a processing result screen on the display screen, a CPU 23 (central processing unit) as a control unit that performs overall control, and a CPU 23. RAM 24 as temporary storage means that works as a work memory at the time of activation, ROM 25 as computer-readable readable recording medium (storage means) in which behavior synthesis programs for operating CPU 23 and various data used therefor are recorded The electrode height of the Ni-P film 12 / Au laminated film 13 using a surface resistance measuring instrument such as a laser displacement meter Measuring the T1, further includes a measurement unit 26 for measuring the surface resistance value by 4 Tanhari.

  Based on the control command read from the ROM 25 into the RAM 24 and various data used for the CPU 4, in addition to the input command from the operation unit 21, the CPU 4 performs measurement control means 231, calculation means 232, determination means 233, Have

  That is, the CPU 4 determines the thickness of the laminated film and the surface resistance value of the laminated film surface in the laminated film in which the first conductive layer 2 and the second conductive layer 3 having two different resistivity are laminated. It has a film thickness measuring means that measures and calculates the film thickness of the second conductive layer 3 having a low resistivity from the film thickness and surface resistance value of the measured laminated film.

  The film thickness measuring means controls the measuring unit 26 to measure the film thickness of the laminated film of the first conductive layer 2 and the second conductive layer 3, and to measure the surface resistance value, Based on the film thickness of the laminated film and the surface resistance value, a calculation means 232 for determining the film thickness of the second conductive layer 3 by a predetermined calculation formula, and determining whether the film thickness of the second conductive layer 3 is within a predetermined range Then, when the film thickness of the second conductive layer 3 is within a predetermined range, it is determined as a non-defective product, and when the film thickness of the second conductive layer 3 is not within the predetermined range, the determination unit 233 determines that the product is defective. have.

  The ROM 25 is configured by a readable recording medium (storage means) such as a hard disk, an optical disk, a magnetic disk, and an IC memory. The control program and various data used for the control program may be downloaded to the ROM 25 from a portable optical disk, a magnetic disk, an IC memory, or the like, or may be downloaded from the hard disk of the computer to the ROM 25, or wirelessly, wired, or the Internet. It may be downloaded to the ROM 25 via the above. A behavioral synthesis program describing a processing procedure for causing a computer to execute the film thickness measurement method of FIG. 8 described later is stored in a computer-readable storage medium, and the film thickness is measured by the computer (CPU 23). .

  FIG. 8 is a flowchart for explaining the operation of the thickness measuring apparatus 20 of FIG.

  As shown in FIG. 8, first, in step S1, the measurement control unit 231 controls the laser displacement meter of the measurement unit 26 to measure the electrode height T1 of the Ni-P film 12 / Au laminated film 13, and the measurement unit 26 is controlled, and the surface resistance value is measured by a four-end needle.

  Next, in step S2, the calculation means 232 calculates the film thickness t2 of the Au laminated film 13 from the above formula (Equation 11) based on the electrode height T1 and the surface resistance, as shown in the above (Equation 12). Can be sought.

  Subsequently, in step S3, the determination unit 233 detects whether or not the film thickness t2 of the Au laminated film 13 obtained in step S2 is within a predetermined range. When the film thickness t2 of the Au laminated film 13 obtained in step S2 is within the predetermined range in step S3 (YES), it is determined as a non-defective product in step S4, and the film thickness t2 of the Au laminated film 13 obtained in step S2 is determined as step. If it is not within the predetermined range in S3 (NO), it is determined as a defective product in step S5. Thereafter, the process ends.

  As described above, according to the first embodiment, in the laminated film in which the first conductive layer 2 having two different resistivities and the second conductive layer 3 thereon are laminated, the film thickness measuring means can A film thickness measurement step of measuring the film thickness and the surface resistance value of the surface of the laminated film, and calculating the film thickness of the second conductive layer 3 having a low resistivity from the measured film thickness and surface resistance value of the laminated film Have. In this film thickness measurement process, the measurement control means 231 controls the measurement unit 26 to measure the film thickness of the laminated film of the first conductive layer 2 and the second conductive layer 3 and to measure the surface resistance value. The control step, the calculation means 232 calculates the film thickness of the second conductive layer 3 by a predetermined calculation formula based on the film thickness and the surface resistance value of the laminated film, and the determination means 233 includes the second conductive It is determined whether or not the film thickness of the layer 3 is within a predetermined range. If the film thickness of the second conductive layer 3 is within the predetermined range, the film is determined to be non-defective, and the film thickness of the second conductive layer 3 is within the predetermined range. If not, it has a determination step for determining a defective product.

  Thus, the two conductive films (the first conductive layer 2 and the second conductive layer 3) laminated are changed to the film thickness of the laminated film of the first conductive layer 2 and the second conductive layer 3 thereon. From the surface resistance value obtained by the four-end needle method, the resistivity and the thickness of the film having the small film thickness (second conductive layer 3) can be easily calculated. In particular, it is suitable for the measurement of the gold film thickness of the laminated film of electroless nickel plating and substitution gold plating.

  In this manner, the semiconductor integrated circuit can be manufactured on the semiconductor wafer substrate by performing Ni plating on the metal pad layer of the semiconductor wafer substrate on which the semiconductor integrated circuit is formed. Using the film thickness measuring device 20, the film thickness of the second conductive layer 3 in which the metal pad layer of the semiconductor wafer substrate on which the semiconductor integrated circuit is formed has been subjected to plating (for example, displacement gold plating) is measured, and non-defective product management is performed. Is done. In this way, it is possible to manufacture and manage a high-quality semiconductor integrated circuit on the semiconductor wafer substrate.

  Although not particularly described in the first embodiment, the measurement unit 26 is controlled to measure the film thickness of the laminated film of the first conductive layer 2 and the second conductive layer 3, and the surface resistance value is measured. Measurement control means 231 for calculating the film thickness of the second conductive layer 3 by a predetermined calculation formula based on the film thickness and surface resistance value of the laminated film, and the film thickness of the second conductive layer 3 Is determined to be within a predetermined range. If the film thickness of the second conductive layer 3 is within the predetermined range, it is determined to be a non-defective product. If the film thickness of the second conductive layer 3 is not within the predetermined range, it is not acceptable. Even when the determination means 233 for determining a non-defective product is provided, the object of the present invention can be achieved in which the film thickness of a conductive laminated film such as an electrode of an electronic component can be measured at high speed with a simple and inexpensive apparatus. it can.

  In the first embodiment, the case where the first conductive layer 2 is an Ni layer and the second conductive layer 3 is an Au layer has been described. However, the present invention is not limited to this, and the first conductive layer 2 is an Ni layer. Needless to say, the second conductive layer 3 may be an Ag layer, the first conductive layer 2 may be a titanium layer, and the second conductive layer 3 may be a Cu layer. Of course, other combinations are possible.

  As mentioned above, although this invention has been illustrated using preferable Embodiment 1 of this invention, this invention should not be limited and limited to this Embodiment 1. It is understood that the scope of the present invention should be construed only by the claims. It is understood that those skilled in the art can implement an equivalent range from the description of the specific preferred embodiment 1 of the present invention based on the description of the present invention and the common general technical knowledge. Patents, patent applications, and documents cited herein should be incorporated by reference in their entirety, as if the contents themselves were specifically described herein. Understood.

  The present invention is a non-defective product management method for measuring the thickness of a thin film such as an electrode of an electronic component by using the film thickness measuring device and film thickness measuring method and film thickness measuring device of a conductive laminated film in the manufacturing process of an electronic device. Manufacturing method for manufacturing a semiconductor integrated circuit, a control program describing a processing procedure for causing a computer to execute each step of the film thickness measuring method, and a computer-readable computer storing the control program In the field of readable storage media, the thickness of the second conductive layer having a low resistivity is calculated from the measured thickness of the laminated film and the surface resistance value. Can be measured at high speed with a simple and inexpensive apparatus.

DESCRIPTION OF SYMBOLS 1 Insulating film 2,3 Conductive layer 4 Underlying conductive layer 11 Insulating substrate 12 Aluminum electrode 13 Ni-P film 14 Au film 15 Laser generator 16 Laser displacement meter 20 Film thickness measuring device 21 Operation part 22 Display part 23 CPU (control means) )
231 Measurement control means 232 Calculation means 233 Determination means 24 RAM
25 ROM
26 Measuring unit

Claims (25)

  In a laminated film in which a first conductive layer having two different resistivities and a second conductive layer thereon are laminated, the film thickness measuring means measures the film thickness of the laminated film with a stylus as a step or a laser Film thickness obtained by measurement using light, measuring the surface resistance value of the surface of the laminated film, and calculating the film thickness of the laminated film and the second conductive layer having a low resistivity from the surface resistance value A film thickness measurement in which the first conductive layer having a high resistivity has a resistivity of at least 10 times and the film thickness is at least 10 times that of the second conductive layer having a low resistivity. Method. The film thickness measurement step includes
A measurement control step in which a measurement control unit controls the measurement unit to measure the film thickness of the laminated film of the first conductive layer and the second conductive layer, and to measure the surface resistance value;
The film thickness measurement method according to claim 1, further comprising: a calculation step of calculating a film thickness of the second conductive layer by a predetermined calculation formula based on the film thickness of the laminated film and the surface resistance value.   The determination means determines whether the film thickness of the second conductive layer is within a predetermined range, and determines that the film is non-defective when the film thickness of the second conductive layer is within the predetermined range. The film thickness measuring method according to claim 2, further comprising a determination step of determining a defective product when the film thickness of the layer is not within a predetermined range.   The film thickness measurement method according to claim 1, wherein the measurement of the surface resistance value on the surface of the laminated film uses a four-end needle method.   The film thickness measuring method according to claim 1, wherein the measurement accuracy of the film thickness of the laminated film is at most 1/10 of the film thickness of the laminated film.   The first conductive layer is a Ni layer and the second conductive layer is an Au layer, the first conductive layer is a Ni layer and the second conductive layer is an Ag layer, or the first conductive layer is a titanium layer. The film thickness measuring method according to claim 1, wherein the second conductive layer is a Cu layer.   The film thickness measuring method according to claim 1, wherein the film thickness of the laminated film of the first conductive layer and the second conductive layer is an electrode height on the semiconductor substrate. In the case where a sheet resistance value is used as the surface resistance value, the predetermined calculation formula is expressed by Equation 13 as the resistivity ρ1, ρ2 of the first conductive layer and the second conductive layer and the film thickness T of the laminated film. The film thickness measuring method according to claim 2.

When a sheet resistance value is used as the surface resistance value, the resistivity ρ0 of the underlying conductive layer and the film thickness t0 are set, and the resistivity ρ1 of the first conductive layer and the second conductive layer laminated on the underlying conductive layer. The film thickness measuring method according to claim 2, wherein the predetermined calculation formula is Equation 14 as ρ 2 and the film thickness T of the laminated film.

In the case where a conductor resistance value is used as the surface resistance value, the predetermined calculation formula is expressed by Equation 15 as the resistivity ρ1, ρ2 of the first conductive layer and the second conductive layer and the film thickness T of the laminated film. The film thickness measuring method according to claim 2.

When a conductor resistance value is used as the surface resistance value, the resistivity ρ0 and the film thickness t0 of the base conductive layer are set, and the resistivity ρ1 of the first conductive layer and the second conductive layer laminated on the base conductive layer. The film thickness measuring method according to claim 2, wherein the predetermined calculation formula is Formula 16 as ρ 2 and the film thickness T of the laminated film.

  In a laminated film in which a first conductive layer having two different resistivities and a second conductive layer thereon are laminated, the film thickness of the laminated film is measured with a stylus as a step or measured using a laser beam. A film thickness measuring means for measuring the surface resistance value of the surface of the laminated film and calculating the film thickness of the laminated film and the thickness of the second conductive layer having a small resistivity from the surface resistance value; A film thickness measuring apparatus in which the first conductive layer having a high resistivity is at least 10 times and the film thickness is at least 10 times that of the second conductive layer having a low resistivity. The film thickness measuring means includes
A measurement control means for controlling the measurement unit to measure the film thickness of the laminated film of the first conductive layer and the second conductive layer and to measure the surface resistance value;
The film thickness measuring apparatus according to claim 12, further comprising a calculation unit that obtains the film thickness of the second conductive layer by a predetermined calculation formula based on the film thickness of the laminated film and the surface resistance value.   It is determined whether or not the film thickness of the second conductive layer is within a predetermined range. If the film thickness of the second conductive layer is within the predetermined range, the film is determined to be non-defective, and the film thickness of the second conductive layer The film thickness measuring apparatus according to claim 13, further comprising a determination unit that determines that the product is defective when the value is not within the predetermined range.   The film thickness measuring apparatus according to claim 12, wherein the measurement of the surface resistance value on the surface of the laminated film uses a four-end needle method.   The film thickness measuring device according to claim 12, wherein the measurement accuracy of the film thickness of the laminated film is at most 1/10 of the film thickness of the laminated film.   The first conductive layer is a Ni layer and the second conductive layer is an Au layer, the first conductive layer is a Ni layer and the second conductive layer is an Ag layer, or the first conductive layer is a titanium layer. The film thickness measuring device according to claim 12, wherein the second conductive layer is a Cu layer.   The film thickness measuring apparatus according to claim 12, wherein a film thickness of the laminated film of the first conductive layer and the second conductive layer is an electrode height on the semiconductor substrate. In the case where a sheet resistance value is used as the surface resistance value, the predetermined calculation formula is expressed by Equation 17 as the resistivity ρ1, ρ2 of the first conductive layer and the second conductive layer and the film thickness T of the laminated film. The film thickness measuring device according to claim 13.

When a sheet resistance value is used as the surface resistance value, the resistivity ρ0 of the underlying conductive layer and the film thickness t0 are set, and the resistivity ρ1 of the first conductive layer and the second conductive layer laminated on the underlying conductive layer. , Ρ2 and the film thickness T of the laminated film, the predetermined calculation formula is Equation 18 .

In the case where a conductor resistance value is used as the surface resistance value, the predetermined calculation formula is expressed by Equation 19 as the resistivity ρ1, ρ2 of the first conductive layer and the second conductive layer and the film thickness T of the laminated film. The film thickness measuring device according to claim 13.

When a conductor resistance value is used as the surface resistance value, the resistivity ρ0 and the film thickness t0 of the base conductive layer are set, and the resistivity ρ1 of the first conductive layer and the second conductive layer laminated on the base conductive layer. as the thickness T of ρ2 and the laminated film, the predetermined formula is a film thickness measuring device according to claim 13 is the number 20.

  23. Using the film thickness measuring apparatus according to claim 12, the film thickness of the second conductive layer obtained by plating a metal pad layer of a semiconductor substrate on which a semiconductor integrated circuit is formed is measured. A method for manufacturing a semiconductor integrated circuit, in which non-defective products are managed and a semiconductor integrated circuit is manufactured on the semiconductor substrate.   12. A control program in which a processing procedure for causing a computer to execute each step of the film thickness measuring method according to claim 1 is described.   A computer readable storage medium storing the control program according to claim 24.

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