Browsing by Author "Fu, DK"

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A novel I-line phase shift mask (PSM) technique for submicron T-Gate formation
(2001)
Fu, DK
;
Chang, HC
;
Fang, CY
;
Lee, CS
;
Chang, EY
Submicron T-gate formation using I-line stepper with phase shift mask (PSM) technique [1,2,3] has become very attractive for GaAs MMIC technology due to its low capital investment and high throughput. In this paper a novel submicron (<0.2mum) T-gate technology using phase shift mask technique is reported. The 8% half-tone PSM was selected for the definition of the isolated narrow space. Before lithography, 2500Angstrom SiN film was deposited on the wafer. After I-line PSM exposure and RIE etch of the silicon nitride film, openings with less than 0.25mum wide were formed on the SiN film. To further reduce the dimension of the openings, the wafer was then deposited addition 500Angstrom nitride and etched back using RIE without any mask. Less than 0.2mum openings were formed on the wafer after the dry etch. The wafer was then coated with another layer of photoresist to form lift-off structure. Gate length of 0.185mum was obtained using this technique. This novel process is a high throughput T-gate process compared to conventional E-beam lithography technology for GaAs MMIC production.
An etch back technique to achieve sub-micron T-gate for GaAsFETs using I-line stepper and phase shift mask (PSM)
(2002)
Fu, DK
;
Chen, SH
;
Chang, HC
;
Chang, EY
;
材料科學與工程學系
In this study, an etch back process with I-line Stepper lithography and phase shift mask (PSM) is demonstrated for sub-micron T-gate fabrication. The opening after I-line lithography using PSM and first RIE etch of silicon nitride is 0.25mum. The opening after second silicon nitride deposition and RIE etch is decreased to 0.16mum. After metal deposition and lift-off, the developed T-shaped gate shows a footprint smaller than 0.2mum. The novel technique is a high throughput T-gate process compared to conventional E-beam technology and can be applied to mass production of high frequency GaAs-based FETs and MMIC.
Novel I-line phase shift mask technique for submicron T-shaped gate formation
(2002-07-01)
Chen, SH
;
Chang, HC
;
Fu, DK
;
Chang, EY
;
Lai, YL
A novel submicron (<0.2 mum) T-shaped gate technology using a phase shift mask (PSM) technique is developed. The 8% half-tone PSM was selected for the definition of the isolated narrow space. Before lithography, a 2000 Angstrom SiN film was deposited on the wafer. After i-line PSM exposure and reactive ion etching (RIE) of the silicon nitride film, openings less than 0.2 mum wide were formed on the SiN film. To further reduce the dimensions of the openings, an additional 566 Angstrom nitride was then deposited on the wafer and etched back using RIE without any mask. An opening of 0.167 mum was formed on the wafer after the dry etching process. The wafer was then coated with another layer of photoresist to form a lift-off structure. The T-shaped gate with a length of 0.167 mum was obtained using this technique. The novel T-shaped gate technology is a high-throughput process for both silicon and compound semiconductor devices.