Study of E-Beam Proximity Effect and Synthesis of Polyimide as E-Beam Resist

• Main Authors: Wei-Chih Chen, 陳威志
• Other Authors: Yu-Der Lee
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/50642349137675079242

碩士 === 國立清華大學 === 化學工程學系 === 88 === Electron beam (e-beam) lithography is one of the most promising candidates for defining fine patterns smaller than 0.1 mm. One of the most serious in e-beam lithography is the proximity effect caused by electron scattering in the resist and the substrate. To obtain good dimension control, the proximity effect has to be suppressed. In the analytical method, the Double-Gaussian proximity function is normally used to describe the exposure intensity distribution (EID). In this thesis, the doughnut method and the two-rectangle method are used to extract the proximity parameters. The proximity effect parameters that we obtained will be substituted into the commercial software PROXECOO to carry out the preliminary dose correction resulted in good proximity effect correction for 0.4 mm pattern. Besides, the e-beam resists have been playing a great role in e-beam lithography, but many resists are not stable for temperature. Polyimide (PI) has excellent thermostability, we introduce the e-beam sensitive group (SO2) to the polymer main chain to develop new PI e-beam resists. PI (6FDA/BAPS) and PI (DSDA/HFBAPP) are verified including structure, viscosity, sensitivity, contrast, thermostabibity, dry etching resistance and other lithography parameters. These properties confirmed they are very good materials as e-beam resists, especially the degraded temperature both are higher than 500 ℃。 In this study, the methods to extract proximity effect parameters are introduced and good 0.4 mm correction results are demonstrated. For the developed new e-beam resists, PI (6FDA/BAPS) is negative type, PI (DSDA/HFBAPP) is positive type and they all have succeeded to form 0.1 mm single line.