Study of Multi-Layer Bottom Antireflective Coatings and Substrate Contamination Effects in Deep UV Lithography

• Main Authors: Hsieh Cheng Feng, 謝境峰
• Other Authors: 施明昌
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/79398812115918523933

碩士 === 國立海洋大學 === 光電科學研究所 === 89 === We propose a new multi-layer bottom antireflective coating (BARC) structure for deep-UV lithography. The mulit-layer BARC structure is composed of TEOS oxide and silicon nitride or silicon oxynitride films. The top TEOS oxide layer is a base contamination free material, which is also as a capping layer as a part of multi-layer BARC structure. The BARC films are deposited by a conventional PECVD system. The optical constants of silicon nitride and silicon oxynitride films can be varied by adjusting the gas flow ratios of SiH4/NH3 and SiH4/N2O, respectively. In a multi-layer BARC, the extinction coefficient (k) of each BARC layer is gradually increased layer by layer, and is the highest at the bottom. The reflectance at the resist/BARC interface can be reduced less than 1% by adding a TEOS/SiN/SiN or a TEOS/SiON/SiON multi-layer BARC structure. The measured swing effect is found significantly reduced by adding the multi-layer BARC on various highly reflective substrates and with large thickness control tolerances. Reduction of substrate contaminations by plasma treatment is very useful. The composition and optical constants of SiN and SiON were changed after oxygen plasma treatment. However, the TEOS SiO2 film can remain to be intact. It is desirable to use the TEOS SiO2 as a capping layer in multi-layer BARC structure.