CN-122018227-A - Correction method and data acquisition method of optical proximity correction model

CN122018227ACN 122018227 ACN122018227 ACN 122018227ACN-122018227-A

Abstract

The application provides a correction method and a data acquisition method of an optical proximity correction model, which are applied to the technical field of semiconductors. The correction method and the data acquisition method comprise the steps of determining a first simulation value of a critical dimension of a test pattern set under initial information of a photoetching condition and a second simulation value of the critical dimension of the test pattern set under adjustment information of the photoetching condition, classifying a plurality of test patterns, and then collecting actual measurement values of the critical dimension respectively by adopting different data acquisition modes for the classified test patterns, so that the accuracy of data acquisition in the modeling process of an optical proximity correction model is ensured, and meanwhile, the calculated quantity of partial actual data acquisition is simplified by utilizing the formula calculation, so that the purposes of reducing labor cost and improving modeling efficiency are achieved.

Inventors

WANG KANG
LUO ZHAOLONG

Assignees

合肥晶合集成电路股份有限公司

Dates

Publication Date: 20260512
Application Date: 20260413

Claims (10)

1. The method for correcting the optical proximity correction model is characterized by comprising the following steps of: determining an actual measurement value of a critical dimension of a test pattern set after exposure on a wafer under initial information of photoetching conditions, and establishing an initial optical proximity effect correction model; Adjusting initial information of the photoetching conditions, and determining a first simulation value of a critical dimension of the test pattern set under the initial information of the photoetching conditions and a second simulation value of the critical dimension of the test pattern set under the adjustment information of the photoetching conditions; Judging whether the difference value of a first simulation value and a second simulation value corresponding to each test pattern in the test pattern set is within a threshold range or not, and classifying a plurality of test patterns in the test pattern set into a first type test pattern and a second type test pattern based on a judging result, wherein the first type test pattern is a test pattern corresponding to the difference value within the threshold range, and the second type test pattern is a test pattern not corresponding to the difference value within the threshold range; Collecting the actual measurement values of the critical dimensions of the first type of test patterns and the second type of test patterns respectively by adopting different data collection modes to obtain collected data, wherein the collected data are the actual measurement values of the critical dimensions of the first type of test patterns or the second type of test patterns after exposure on a wafer under the adjustment information of the photoetching conditions; and correcting the initial optical proximity effect correction model by utilizing the collected data to obtain a target optical proximity effect correction model.
2. The method of claim 1, wherein the lithographic conditions include energy of illumination, focus, or light source.
3. The correction method as set forth in claim 2, wherein said information for adjusting said lithographic conditions includes information for adjusting the shape of a light source in said lithographic conditions.
4. The correction method as set forth in claim 1, wherein the threshold range is smaller than a set value, the set value being 1.5nm.
5. The method of calibrating according to claim 1, wherein the step of collecting critical dimension actual measurement values for the first type of test pattern and the second type of test pattern respectively using different data collection methods comprises: calculating an actual measurement value of the critical dimension of the first type of test patterns after exposure on the wafer under the adjustment information of the photoetching conditions by using a preset formula; And determining the actual measurement value of the critical dimension of the second type of test patterns after exposure on the wafer under the adjustment information of the photoetching conditions by using an actual exposure mode.
6. The correction method as set forth in claim 5, wherein the predetermined formula is: A’=(A/a)*a’; Wherein A 'is an actual measurement value of the critical dimension of the first type of test pattern after exposure on the wafer under the adjustment information of the lithography condition, A is an actual measurement value of the critical dimension of the first type of test pattern after exposure on the wafer under the initial information of the lithography condition, a' is a second simulation value of the critical dimension of the first type of test pattern under the adjustment information of the lithography condition, and a is a first simulation value of the critical dimension of the first type of test pattern under the initial information of the lithography condition.
7. The data acquisition method of the optical proximity correction model is characterized by comprising the following steps of: providing a test pattern set, and determining an actual measurement value of a critical dimension of the test pattern set after exposure on a wafer under initial information of a photoetching condition; Adjusting the information of the photoetching conditions, and determining a first simulation value of the critical dimension of the test pattern set under the initial information of the photoetching conditions and a second simulation value of the critical dimension of the test pattern set under the adjustment information of the photoetching conditions; Judging whether the difference value of a first simulation value and a second simulation value corresponding to each test pattern in the test pattern set is within a threshold range or not, and classifying a plurality of test patterns in the test pattern set into a first type test pattern and a second type test pattern based on a judging result, wherein the first type test pattern is a test pattern corresponding to the difference value within the threshold range, and the second type test pattern is a test pattern not corresponding to the difference value within the threshold range; And re-collecting the actual measurement values of the critical dimensions of the first type of test patterns and the second type of test patterns respectively by adopting different data collection modes to obtain collected data, wherein the collected data are the actual measurement values of the critical dimensions of the first type of test patterns or the second type of test patterns after exposure on a wafer under the adjustment information of the photoetching conditions.
8. The data collection method according to claim 7, wherein the step of collecting the actual measurement values of the critical dimensions of the first type of test patterns and the second type of test patterns respectively by using different data collection modes comprises: calculating an actual measurement value of the critical dimension of the first type of test patterns after exposure on the wafer under the adjustment information of the photoetching conditions by using a preset formula; And determining the actual measurement value of the critical dimension of the second type of test patterns after exposure on the wafer under the adjustment information of the photoetching conditions by using an actual exposure mode.
9. The data acquisition method of claim 8, wherein the predetermined formula is: A’=(A/a)*a’; Wherein A 'is an actual measurement value of the critical dimension of the first type of test pattern after exposure on the wafer under the adjustment information of the lithography condition, A is an actual measurement value of the critical dimension of the first type of test pattern after exposure on the wafer under the initial information of the lithography condition, a' is a second simulation value of the critical dimension of the first type of test pattern under the adjustment information of the lithography condition, and a is a first simulation value of the critical dimension of the first type of test pattern under the initial information of the lithography condition.
10. A computer-readable storage medium, on which a computer program is stored, which computer program, when being executed by a processor, implements the steps of the correction method according to any one of claims 1 to 6 or the steps of the data acquisition method according to any one of claims 7 to 9.

Description

Correction method and data acquisition method of optical proximity correction model Technical Field The application relates to the technical field of semiconductors, in particular to a correction method and a data acquisition method of an optical proximity correction model. Background With the development of integrated circuits, semiconductor fabrication technology is continually advancing toward smaller dimensions, and the feature size of semiconductor devices is even smaller than the optical wavelength of the light sources used in photolithography processes. In this case, the pattern on the mask is deformed during transfer due to the diffraction effect of light, i.e., an optical proximity effect (Optical Proximity Effect) occurs. The optical proximity effect can cause a large difference between the actual pattern projected onto the wafer and the designed target pattern, thereby affecting the lithographic quality of adjacent pattern areas on the mask pattern, and thus affecting circuit performance and production yields. In order to eliminate the influence of the optical proximity effect, an optical proximity correction (Optical Proximity Correction, OPC) method is generally used. The method uses computer software to correct the original pattern to be exposed on the semiconductor substrate of the silicon wafer to obtain a target pattern different from the original pattern, then makes a photomask according to the target pattern, and when photoetching is carried out, the pattern obtained by utilizing the photomask to project on the semiconductor substrate can be almost the same as the original pattern, thereby compensating the problem caused by the optical proximity effect. The lithography condition is an indispensable modeling parameter in OPC modeling, that is, the change of the lithography condition directly affects the reflectivity of the bottom layer of the light source, and further affects the optical proximity effect. At present, aiming at the influence of lithography conditions on OPC modeling, a common solution is to collect wafer data required by modeling again as long as a light source is changed, and the collection and screening of the data are complex and time-consuming, so that the accuracy of feedback data is intangibly increased, the correction time is prolonged, and the production cost is increased. Disclosure of Invention One of the purposes of the application is to provide a correction method and a data acquisition method for an optical proximity correction model, optimize and diversify the data acquisition modes in the modeling and correction processes of the optical proximity correction model, weaken the complexity of data acquisition, reduce the data acquisition amount, reduce the modeling cost and ensure the accuracy of the model. In order to achieve the above object, an embodiment of the present application provides a method for correcting an optical proximity correction model, including: And determining an actual measurement value of the critical dimension of the test pattern set after exposure on the wafer under the initial information of the photoetching condition, and establishing an initial optical proximity effect correction model. And adjusting the initial information of the photoetching conditions, and determining a first simulation value of the critical dimension of the test pattern set under the initial information of the photoetching conditions and a second simulation value of the critical dimension of the test pattern set under the adjustment information of the photoetching conditions. Judging whether the difference value of a first simulation value and a second simulation value corresponding to each test pattern in the test pattern set is within a threshold range or not, and classifying a plurality of test patterns in the test pattern set into a first type test pattern and a second type test pattern based on a judging result, wherein the first type test pattern is a test pattern corresponding to the difference value within the threshold range, and the second type test pattern is a test pattern not corresponding to the difference value within the threshold range. And re-collecting the actual measurement values of the critical dimensions of the first type of test patterns and the second type of test patterns respectively by adopting different data collection modes to obtain collected data, wherein the collected data are the actual measurement values of the critical dimensions of the first type of test patterns or the second type of test patterns after exposure on a wafer under the adjustment information of the photoetching conditions. And correcting the initial optical proximity effect correction model by utilizing the collected data to obtain a target optical proximity effect correction model. Alternatively, the lithographic conditions may include the energy of the illumination, the focus or the light source. Optionally, the information for adjusting the lithography conditi