CN-121978194-A - Precise detection method for gas escape in spin-on carbon material curing process

Abstract

The invention discloses a precise detection method for gas escape in a spin-coated carbon material curing process, and belongs to the technical field of chemical detection. The invention can solve the quantitative detection problem of the gas escaping from the spin-on carbon material in the high-temperature process, thereby guiding the design of the spin-on carbon molecular structure, reducing the film defects caused by the deflation of the spin-on carbon material in the process, such as micropores, unevenness and insufficient filling, ensuring the strict requirement of high-precision pattern transfer required by the process, improving the overall yield and ensuring the reliability of devices.

Inventors

• LIN HAOSHENG
• Li Roumei
• LAN XIAOYU
• LI QIONGYA

Assignees

• 江苏雅睿半导体材料有限公司

Dates

Publication Date

20260505

Application Date

20260318

Claims (9)

1. 1. The precise detection method for gas escape in the process of curing the spin-coated carbon material is characterized by comprising the following steps of: (1) Coating a spin-on carbon sample on a substrate, and then rotating and drying the substrate to form a spin-on carbon layer; (2) Placing a substrate containing a spin-coated carbon layer on a test carrier, and adopting TPD-MS to perform in-situ analysis on gas release behaviors of a sample in a heating process under helium atmosphere; (3) After the TPD is finished, the air flow is switched to the adsorbate gas, and the sample is exposed to the adsorbate gas for 30-60min at the set adsorption temperature to reach the adsorption equilibrium. And then, switching the gas flow back to helium, starting temperature program control and mass spectrum data acquisition, heating the adsorbate gas by the system, and monitoring the signal intensity of m/z in real time by using a mass spectrum, thereby realizing quantitative detection of the gas.
2. 2. The precise detection method for gas escape in the curing process of the spin-on carbon material according to claim 1, wherein the spin-on carbon sample comprises, by mass, 5-25% of spin-on carbon resin, 0.01-0.3% of surfactant, 40-70% of PGMEA and 10-40% of PGME.
3. 3. The precise detection method for gas evolution during the curing process of the spin-on carbon material according to claim 2, wherein the spin-on carbon resin has a structure as shown in formula 1: general formula 1 Wherein AR1 and AR2 are benzene rings or naphthalene rings which may have a substituent, and when n is 0 or 1, n=0, AR1 and AR do not form a crosslinked structure between aromatic rings of AR1 and AR2 via Z, and when n=1, AR1 and AR2 form a crosslinked structure between aromatic rings of AR1 and AR2 via Z; Z is a single bond or any one selected from the following structures: ; Y has a structure as shown in formula 2: General formula 2 In the general formula 2, R1 is selected from a single bond or a divalent organic group with 1-20 carbon atoms, and R2 is selected from a hydrogen atom or a monovalent organic group with 1-20 carbon atoms.
4. 4. The method for precisely detecting gas evolution during the curing process of a spin-on carbon material according to claim 2, wherein the surfactant is 3M fluorocarbon surfactant FC-4430.
5. 5. The method for precisely detecting gas escape during the curing process of a spin-on carbon material according to claim 1, wherein the substrate in step (1) is a silicon wafer; The rotating speed of the rotary heating is 1500 revolutions per minute, the heating temperature is 240 ℃, and the heating time is 60s.
6. 6. The method for precisely detecting the escape of gas during the curing process of a spin-on carbon material according to claim 1, wherein the heating process in the step (2) is a programmed temperature rise from room temperature to 400 ℃ at a temperature rise rate of 10 ℃ per minute, and maintained at a constant temperature of 400 ℃ for 2 minutes.
7. 7. The method for precisely detecting gas evolution during the curing process of a spin-on carbon material according to claim 1, wherein the adsorbate gas in step (3) is selected from any one of NH 3 、CO 2 , CO and H 2 .
8. 8. The precise detection method for gas escape in the spin-on carbon material curing process of claim 1, wherein in the step (3), the adsorbed gas is reheated to obtain desorption gas, and the desorption gas is introduced into a gas chromatograph-mass spectrometer for separation and identification, so as to realize quantitative detection of the gas.
9. 9. The method for precisely detecting the escape of gas during the curing process of the spin-on carbon material according to claim 1 or 8, wherein the systematic heating method in step (3) is to raise the temperature from room temperature to 350-500 ℃ at a temperature raising rate of 5-20 ℃ per minute and keep the temperature for 2min.

Description

Precise detection method for gas escape in spin-on carbon material curing process Technical Field The invention relates to the technical field of chemical detection, in particular to a precise detection method for gas escape in a spin-on carbon material curing process. Background In semiconductor manufacturing, photolithography is a precision manufacturing technique in which a circuit pattern designed on a reticle is transferred to a wafer through a photoresist or a hard mask (Hardmask) to perform fine patterning. With the development of integrated circuits toward high integration and high speed, the pattern size is continuously shrinking, and particularly, high resolution (< 56 nm) patterns need to be transferred to a wafer by etching, and photoresist needs to be matched with an immersion exposure technology (ArFi) to realize the transfer of the high resolution patterns from a mask. However, such Deep Ultraviolet (DUV) photoresists cannot obtain sufficient etching resistance due to their high resolution designs, and thus it is difficult to meet the pattern transfer requirements required for high aspect ratio patterns on the final wafer. For this reason, the industry has been developing hard masks Hardmask that achieve high aspect ratio patterns on wafers because of the extremely high etch resistance of high carbon content designs. In early days, the hard mask was typically realized by depositing amorphous carbon on the wafer by Chemical vapor deposition (Chemical VaporDeposition, CVD). Although the CVD method can obtain a carbon film with a high carbon content (about 100% C content), defects such as voids, slits (sea) and the like are easily formed in the trench due to the physical properties of vapor deposition, resulting in a film with a dense defect. Therefore, in recent years, liquid phase spin coating is used to prepare organic hard masks, i.e., organic compounds with high carbon content (higher than 85% C content) are chemically synthesized as spin-coated carbon on wafers, and crosslinked and cured at high temperature to form organic carbon-containing hard masks. Although spin-coating carbon material can avoid Void and slit defects of CVD amorphous carbon, the polymer organic used in the spin-coating carbon material is cured and crosslinked at high temperature, and involves chemical condensation/polycondensation reaction, which is easy to release small molecular volatile matters and gasify at high temperature, so that the released gas causes defects of the film, thereby causing deformation, warpage or displacement of the pattern, even forming micropores (Void) or pinholes (Pinhole), reducing compactness, mechanical strength and adhesion of the film, and possibly polluting the process chamber and the wafer surface, affecting the integrity of the pattern. Therefore, how to realize quantitative detection of gas evolution of spin-coated carbon materials under high temperature conditions is a problem that needs to be solved by those skilled in the art. Disclosure of Invention In view of the above, the present invention provides a precise detection method for gas evolution during the curing process of spin-on carbon materials. The invention uses TPD-MS technology to realize quantitative detection of gas escape of spin-coated carbon material under high temperature, and ensures the accuracy and reliability of test data by an instrument. The invention solves the problem of quantitative detection of escaping gas generated by spin-coating carbon materials at high temperature, and provides reliable material foundation and process guarantee for high-precision pattern transfer. In order to achieve the above purpose, the invention adopts the following technical scheme: a precise detection method for gas escape in the process of curing a spin-on carbon material comprises the following steps: (1) Coating a spin-on carbon sample on a substrate, and then rotating and drying the substrate to form a spin-on carbon layer; (2) Placing a substrate containing a spin-coated carbon layer on a test carrier, and adopting TPD-MS to carry out in-situ analysis on the gas release behavior of a sample in the heating process under helium atmosphere to obtain an m/z ion flow curve, wherein the change of the gas release rate along with the temperature/time is reflected; (3) After the TPD is finished, the air flow is switched to the adsorbate gas, and the sample is exposed to the adsorbate gas for 30-60min at the set adsorption temperature (normal temperature or low temperature) to reach the adsorption equilibrium. And then, switching the gas flow back to helium, starting temperature program control and mass spectrum data acquisition (completed by using Shimadzu QP2010 Ultra 11), heating the adsorbate gas at a constant speed by the system, and monitoring the signal intensity of m/z in real time by mass spectrum so as to realize quantitative detection of the gas. The core principle of the TPD-MS is that a sample pre-adsorbed with a certai