KR20170031819A - System and Method for Metrology of Semiconductor Pattern - Google Patents

Abstract

The semiconductor pattern measuring system according to an embodiment of the present invention generates a reference spectral difference value based on a difference between a plurality of reference spectral spectra acquired from each of a plurality of reference objects as semiconductor integrated devices, A spectral analysis section configured to generate an analysis object spectrum difference value based on a difference between any one of the spectral spectra to be analyzed and the plurality of reference spectral spectra obtained from the plurality of reference objects and a reference parameter acquired from each of the plurality of reference objects And a parameter analyzer configured to generate a reference parameter difference value and to derive a measurement parameter of the analyte based on the reference spectral difference value, the reference parameter difference value, and the analyzed spectral difference value.

Description

Technical Field [0001] The present invention relates to a system and a method for measuring a semiconductor pattern,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical measurement technique, and more particularly, to a semiconductor pattern measurement system and method.

Structures constituting semiconductor integrated circuits are decreasing in size and increasing in complexity.

During the process of the semiconductor integrated circuit, or after the process is completed, the three-dimensional shape of the structure is precisely measured and the measurement result is applied to the process to improve the production yield.

Regardless of the method used for pattern measurement, the accuracy and speed of measurement are required for the analysis of complex structures that make up a semiconductor integrated circuit.

Embodiments of the present technology can provide a semiconductor pattern measurement system and method that can acquire information on a structure with a small amount of computation and high speed.

The semiconductor pattern measuring system according to an embodiment of the present invention generates a reference spectral difference value based on a difference between a plurality of reference spectral spectra acquired from each of a plurality of reference objects as semiconductor integrated devices, A spectral analysis unit configured to generate a spectrum difference value to be analyzed based on a difference between any one of the plurality of reference spectral spectra and the spectral spectrum to be analyzed acquired from the spectral analysis unit; And generating a reference parameter difference value based on a difference between reference parameters acquired from each of the plurality of reference objects, and calculating a reference parameter difference value based on the reference spectral difference value, the reference parameter difference value, And a parameter analysis unit configured to derive the measurement parameter.

A semiconductor pattern measuring method according to an embodiment of the present invention is a semiconductor pattern measuring method of a semiconductor pattern measuring system, wherein the semiconductor pattern measuring system includes a plurality of reference spectral spectra obtained from each of a plurality of reference objects, Generating a reference spectral difference value based on the difference; The semiconductor pattern measuring system comprising: generating a reference parameter difference value based on a difference between reference parameters acquired from each of the plurality of reference objects; The semiconductor pattern measuring system comprising: generating an analysis target spectrum difference value based on a difference between any one of the spectral spectra to be analyzed and the plurality of reference spectral spectra acquired from an analyte as a semiconductor integrated device; And the semiconductor pattern measuring system deriving measurement parameters of the analyte based on the reference spectral difference value, the reference parameter difference value, and the spectral difference value to be analyzed.

According to this technique, the shape information of the object to be analyzed can be derived on the basis of the difference between the spectra. Therefore, it is possible to omit the process of separately converting or analyzing the spectrum of the object to be analyzed, and it is possible to derive the shape of the object at a high speed, and the computational load and system load for the object can be drastically reduced.

1 is a configuration diagram of a semiconductor pattern measuring system according to an embodiment.
2 is a flowchart for explaining a semiconductor pattern measuring method according to an embodiment.
3 to 5 are reference views for explaining a pattern measuring method according to an embodiment.
6 is a reference diagram for explaining a pattern measurement method for a semiconductor wafer according to an embodiment.

Hereinafter, embodiments of the present technology will be described in more detail with reference to the accompanying drawings.

1 is a configuration diagram of a semiconductor pattern measuring system according to an embodiment.

Referring to FIG. 1, a pattern measurement system 10 according to an embodiment includes a controller 110, an operator interface (UI) 120, a memory 130, a first measurement device 140, a second measurement device 150 ), A spectrum analyzer 160, and a parameter analyzer 170.

The controller 110 may be configured to control the overall operation of the semiconductor pattern measurement system 10. [

Operator interface 120 may include an input device and an output device. Operation parameters such as an operator's command, data, and the like can be provided through the input device. In addition, the operation status, processing results, and the like of the semiconductor pattern measuring system 10 can be output through the output device.

The memory 130 may include a main memory and an auxiliary memory, and may store programs, control data, application programs, operating parameters, processing results, and the like necessary for the semiconductor pattern measuring system 10 to operate.

The first measurement device 140 may be configured to acquire a spectral spectrum for at least two reference objects and an object to be analyzed.

In one embodiment, the first measurement device 140 may be selected from among devices capable of measuring the spectral spectrum for the object. In one embodiment, the first measuring device 140 may be a spectroscopic ellipsometer, a reflectometer, a scatterometer, or a spectroscopic spectrometer using an interferometer. The first measuring device 140 may use a light source having coherence or an incoherent light source. In one embodiment, the first measurement device 140 may obtain a spectrum and an interference image for the object S by classifying a TE (Transverse Electronic wave) mode and a TM (Transverse Magnetic wave) mode.

The first measurement device 140 may be configured to measure a local phase and amplitude change for each position by measuring the object S at each X-Y position.

The reference spectral spectrum, which is the spectral spectrum of a plurality of reference objects measured by the first measurement device 140, and the spectral spectrum to be analyzed, which is the spectral spectrum of the object to be analyzed, may be stored in the memory 130.

The second measuring device 150 may be selected from devices that directly measure the measurement parameters for at least two reference objects. In an embodiment, the second measuring device 150 may be an apparatus such as a scanning electron microscope (SEM), an optical critical dimension (OCD), an atomic force microscope (AFM), or a transmission electron microscope But is not limited thereto.

The reference parameter, which is a measurement parameter for each of a plurality of reference objects measured directly by the second measurement device 150, may be stored in the memory 130, matching the reference spectral spectrum of each reference object. Accordingly, the reference spectral spectrum for each of a plurality of reference objects may be stored in the memory 130 together with reference parameters of the reference object.

)와 위상지연값(

)으로 파장에 대한 기준 분광 스펙트럼을 도출할 수 있다.The spectrum analyzer 160 may calculate the difference between each reference spectral spectrum for the reference spectral spectrum obtained from each of the plurality of reference objects to generate a reference spectral difference value. In one embodiment, the spectrum analyzer 160 irradiates each reference object with a light source and calculates a reflection ratio (

) And the phase delay value (

), It is possible to derive a reference spectral spectrum for the wavelength.

Therefore, the spectrum analyzer 160 may calculate a spectral difference value for each wavelength with reference to the reference spectral spectrum of at least two reference objects, and generate the reference spectral difference value.

The spectrum analyzer 160 may also select one of a plurality of reference spectral spectra, and calculate a spectral difference value between the selected reference spectral spectrum and the spectral spectrum to be analyzed to generate the spectral difference value to be analyzed.

The parameter analyzing unit 170 can generate a difference value between each reference parameter of at least two reference objects as a reference parameter difference value for a plurality of reference objects.

In addition, the parameter analyzing unit 170 can be configured to derive the measurement parameters of the object to be analyzed based on the spectrum difference value to be analyzed, the reference spectrum difference value, and the reference parameter difference value.

2 is a flowchart for explaining a semiconductor pattern measuring method according to an embodiment.

In one embodiment, it is assumed that the reference spectral spectrum A and the reference spectral spectrum B for the reference objects A and B are obtained (S101). The spectrum analyzer 160 may generate a reference spectrum difference value by calculating a spectral difference value at each wavelength with reference to the reference spectral spectrum A and the reference spectral spectrum B (S103). In addition, the parameter analyzer 170 may obtain the reference parameter A for the reference object A and the reference parameter B for the reference object B (S105), and generate a reference parameter difference value from the difference between the two reference parameters (S107).

When the spectral spectrum C to be analyzed for the object C to be analyzed is obtained (S109), the spectrum analyzer 160 obtains the spectral intensity C of the object A based on any one of the plurality of reference objects, for example, the reference spectral spectrum A and the spectral spectrum C A spectrum difference value to be analyzed can be obtained (S111).

Then, the parameter analyzer 170 can derive the measurement parameters for the object C to be analyzed based on the reference spectrum difference value, the reference parameter difference value, and the analysis object spectrum difference value (S113). In this case, it goes without saying that the parameter analyzer 170 must use the reference spectral difference value and the reference parameter difference value associated with the analyzed object A referred to when the spectrum analyzer 160 acquires the spectral difference value.

In one embodiment, the parameter analyzer 170 can derive a measurement parameter for the analyte C by associating a reference spectral difference value with the ratio of the spectrum under analysis to the reference spectral difference value associated with the analyte A have.

The parameter analysis unit 170 may store the measurement parameters for the analysis object in the memory 130 (S115). At this time, the spectral spectrum to be analyzed for the analyte can be stored together.

In this embodiment, after the spectral spectrum of the analyte is acquired, it is not subjected to a procedure such as regression analysis or fitting to a pre-stored spectral library. However, measurement parameters are inferred from the spectral spectrum to be analyzed based on the reference spectral difference value and the reference parameter difference value generated for a plurality of reference objects.

The spectrum (? Or?) Obtained by the change of the measurement parameter is non-linear. However, there may be a linear section in the change in the micro-section where the shape difference of the measurement object exists within a predetermined range (for example, 0 to 20 nm). Therefore, it is possible to obtain in advance the relationship between the spectral relationships (reference spectral difference values) of two reference objects in the section having linearity and the parameters (reference parameter difference values) between the two reference object parameters at this time, (Spectral difference value to be analyzed) between the reference spectral spectra of the object to be measured, the measurement parameters of the object to be analyzed can be derived.

3 to 5 are reference views for explaining a pattern measuring method according to an embodiment.

Fig. 3 shows the pattern shape (a) of the first reference object and the reference spectral spectrum (b) obtained therefrom. Fig. 4 shows the pattern shape (a) of the second reference object and the difference (b) of the reference spectra obtained therefrom.

When a second reference spectral spectrum (not shown) obtained from the pattern shape of the second reference object (Fig. 4 (a)) is obtained, the first reference spectral spectrum b)) can be obtained.

That is, FIG. 4 (b) shows the difference between the first reference spectral spectrum for the pattern shape of the first reference object and the second reference spectral spectrum for the pattern shape of the second reference object.

The spectrum analyzer 160 can obtain a reference spectrum difference value (e.g., D1) at a specific wavelength.

The parameter analyzing unit 170 can obtain the actual parameter which the spectrum means at the corresponding wavelength. The actual parameter may be, for example, the thickness TH1 from the surface of the first reference object to the pattern having the highest height and the thickness TH2 from the surface of the second reference object to the pattern having the highest height. When the actual parameters are obtained, the parameter analyzing unit 170 can calculate the difference between them as the reference parameter difference value (TH2-TH1).

Fig. 5 shows the pattern shape (a) of the object to be analyzed and the difference (b) of the spectrum of the object of analysis obtained therefrom.

The spectrum analyzer 160 analyzes the spectrum of the object (not shown) to be analyzed and the first reference spectral spectrum (for example, the first reference object) of the first reference object at a wavelength at which the reference spectral difference value is calculated for the first and second reference objects (Fig. 3 (b)) can be obtained by the difference in the spectrum of interest (D2 in Fig. 5 (b)).

The parameter analyzing unit 160 analyzes the parameter change for the analysis object by associating the reference spectrum difference value TH2-TH1 with the ratio of the analysis target spectrum difference value D2 to the reference spectrum difference value D1. Value can be deduced. Then, the measurement parameter of the analyte can be derived and stored based on the inferred parameter change value.

In one embodiment, it is assumed that the thickness TH1 from the surface of the first reference object to the pattern having the highest height is 24 nm, and the thickness TH2 from the surface of the second reference object to the pattern having the highest height is 44 nm . It is assumed that the difference D1 of the spectrum at the wavelength representing the parameter is 0.35.

Then, the reference spectral difference value can be obtained as 0.35, and the reference parameter difference value can be obtained as 20 nm.

로 계산될 수 있다.If the spectral difference value (D2) to be analyzed is 0.035 at the corresponding wavelength of the spectrum to be analyzed, the parameter change value of the analyte is

Lt; / RTI >

Therefore, the thickness TH3 from the surface of the analyte to the pattern having the highest height can be derived as 20 nm + 2 nm = 22 nm.

6 is a reference diagram for explaining a pattern measurement method for a semiconductor wafer according to an embodiment.

Semiconductor wafers can generally be divided into a plurality of regions (dies). Even if a semiconductor integrated device is formed on such a semiconductor wafer and a spectral spectrum is obtained for the entire semiconductor wafer, it can not be expressed by a specific mathematical relation.

However, if a plurality of such semiconductor wafers are manufactured, the spectral spectrum extracted for a specific region of each of a plurality of semiconductor wafers, for example, a specific die, may have substantially the same pattern.

Therefore, a plurality of semiconductor wafers are used as reference wafers REF1 and REF2, and a reference spectral spectrum is obtained for each region (die, D), and a reference spectral difference value is calculated. Also, a reference parameter is directly obtained for each region (D), and a reference parameter difference value is calculated. Then, when there is the semiconductor wafer OBJ to be analyzed, the same region (D1_REF1, D1_REF2) of the reference semiconductor wafer corresponds to the spectral spectrum to be analyzed of the specific region (die, D1_OBJ) of the semiconductor wafer OBJ to be analyzed The reference spectral spectrum, the reference spectral difference value, and the reference parameter difference value calculated on the basis of the measured spectral spectra, the measurement parameters of the semiconductor wafer to be analyzed can be easily derived.

Accordingly, the spectrum analyzer 160 of the semiconductor pattern measuring apparatus 10 of the present embodiment divides the reference spectral spectrum for each of the regions Dn_REF1 and Dn_REF2 of the plurality of reference objects and stores them in the regions Dn_REF1 and Dn_REF2, The reference spectrum difference value can be generated. Likewise, the parameter analyzing unit 170 may obtain reference parameter values for each of the regions Dn_REF1 and Dn_REF2 of a plurality of reference objects, and obtain reference parameter difference values for each of the regions Dn_REF1 and Dn_REF2.

Further, the spectrum analyzer 160 acquires the spectral spectrum to be analyzed for each region Dn_OBJ of the object to be analyzed. The reference spectral spectrum acquired previously for the corresponding region (D1_REF1, D1_REF2) of the reference object with respect to the region D1_OBJ to be analyzed can be extracted to acquire the spectral difference value to be analyzed. The parameter analyzer 170 extracts a reference parameter difference value and a reference spectrum difference value that are stored in advance in the corresponding areas D1_REF1 and D1_REF2, Measurement parameters can be derived.

The above-described series of processes for measuring the shape of the object to be analyzed can be produced as a program executable on a computer, and the program can be stored on a computer-readable recording medium.

Thus, those skilled in the art will appreciate that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the embodiments described above are to be considered in all respects only as illustrative and not restrictive. The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

10: Semiconductor pattern measurement system
110: controller
120: Operator interface
130: memory
140, 150: Measuring device
160: Spectrum analysis section
170: Parameter analysis section

Claims (14)

A reference spectral difference value is generated based on a difference between a plurality of reference spectral spectrums obtained from each of a plurality of reference objects, which are semiconductor integrated devices, respectively, and the spectral spectra to be analyzed obtained from the analyte as the semiconductor integrated device and the plurality of reference spectral spectra A spectrum analyzer configured to generate a spectrum difference value to be analyzed based on a difference of any one of the spectra; And
A reference parameter difference value is generated based on a difference between reference parameters acquired from each of the plurality of reference objects, and measurement of the analysis object based on the reference spectrum difference value, the reference parameter difference value, A parameter analyzer configured to derive a parameter;
The semiconductor pattern measuring system comprising: The method according to claim 1,
Wherein the parameter analyzing unit is configured to derive the measurement parameter based on the reference spectral difference value and the reference parameter difference value associated with the reference object referenced when the spectrum analyzer generates the spectral difference value to be analyzed, . The method according to claim 1,
Wherein the spectrum analyzer is configured to generate the reference spectral difference value in a linear interval of the plurality of reference spectral spectra. The method according to claim 1,
Wherein the parameter analyzing unit is configured to infer the parameter change value by relating the reference parameter difference value to the ratio of the spectrum difference value to be analyzed to the reference spectrum difference value. The method according to claim 1,
Wherein the spectrum analyzing unit generates the reference spectral difference value based on the plurality of reference spectral spectra acquired in the same area of each of the plurality of reference objects, To generate a spectrum difference value to be analyzed,
And the parameter analyzing unit is configured to obtain the reference parameter difference value in the same area. The method according to claim 1,
And a first measuring device configured to obtain the plurality of reference spectroscopic spectra and the spectroscopic spectrum to be analyzed. The method according to claim 6,
Wherein the first measuring apparatus is configured to include any one of a spectroscopic ellipsometer, a spectroscopic reflectometer, and a spectroscopic scattering system. The method according to claim 1,
And a second measurement device configured to directly measure the reference parameter for each of the plurality of reference objects. 9. The method of claim 8,
Wherein the second measuring device is selected from a scanning electron microscope (SEM), an optical critical dimension (OCD), an atomic force microscope (AFM), and a transmission electron microscope (TEM). A semiconductor pattern measuring method of a semiconductor pattern measuring system,
The semiconductor pattern measuring system comprising: generating a reference spectral difference value based on a difference between a plurality of reference spectral spectra obtained from each of a plurality of reference objects, each being a semiconductor integrated device;
The semiconductor pattern measuring system comprising: generating a reference parameter difference value based on a difference between reference parameters acquired from each of the plurality of reference objects;
The semiconductor pattern measuring system comprising: generating an analysis target spectrum difference value based on a difference between any one of the spectral spectra to be analyzed and the plurality of reference spectral spectra acquired from an analyte as a semiconductor integrated device; And
The semiconductor pattern measuring system deriving a measurement parameter of the analyte based on the reference spectral difference value, the reference parameter difference value, and the spectral difference value to be analyzed;
The semiconductor pattern measuring method comprising: 11. The method of claim 10,
Wherein the step of deriving the measurement parameter includes deriving the measurement parameter based on the reference spectral difference value and the reference parameter difference value associated with the reference object referenced when generating the analysis target spectrum difference value, . 11. The method of claim 10,
Wherein generating the reference spectral difference value comprises generating the reference spectral difference value in a linear interval of the plurality of reference spectral spectra. 11. The method of claim 10,
Wherein deriving the metrology parameter comprises deriving a parameter change value by associating the reference parameter difference value with a ratio of the spectrum difference value to be analyzed to the reference spectrum difference value, . 11. The method of claim 10,
Wherein the step of generating the reference spectral difference value is a step of generating the reference spectral difference value based on the plurality of reference spectral spectra acquired in the same area of each of the plurality of reference objects,
Wherein generating the reference parameter difference value comprises generating the reference parameter difference value in the same area,
Wherein the step of generating the spectrum difference value to be analyzed is a step of generating the spectrum difference value to be analyzed based on the spectral spectrum to be analyzed acquired in the same area of the analysis object.

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