Low Temperature Photo-CVD by Two-Step Excitation

Research Project

Project/Area Number	58420027
Research Category	Grant-in-Aid for General Scientific Research (A)
Allocation Type	Single-year Grants
Research Field	電子材料工学
Research Institution	Tohoku University
Principal Investigator	MIKOSHIBA Nobuo 東北大学, 電通研, 教授 (70006279)
Project Period (FY)	1983 – 1985
Project Status	Completed (Fiscal Year 1985)
Budget Amount *help	¥35,400,000 (Direct Cost: ¥35,400,000) Fiscal Year 1985: ¥4,000,000 (Direct Cost: ¥4,000,000) Fiscal Year 1984: ¥8,000,000 (Direct Cost: ¥8,000,000) Fiscal Year 1983: ¥23,400,000 (Direct Cost: ¥23,400,000)
Keywords	Two-Step Excitation / Photo-CVD / 低温プロセス
Research Abstract	In LSI process, low temperature CVD technologies of metal, insulator, and semiconductor films without charged particle damage are required. In order to deposite high quality and high density thin films at low temperatures, a gas phase excitation and a surface reaction must be separated and independently controlled. We proposed a "Hybrid-Excitation CVD (HE-CVD)" in which plasma is used for a gas phase excitation and UV light irradiation for a surface reaction. We have carried out detailed studies on HE-CVD for aluminum deposition for three years (1983-1985) and obtained the following results. (1) We measured the UV absorption spectrum of trimethyl-aluminum(TMA). We decided to use a Xe lamp for HE-CVD. (2) We have investigated a vapor decomposition mechanism of TMA. In order to obtaine A1 films without carbon incorporation, it must be necessary to use hydrogen which reacts with methyl radical to generate methane. The excitation method which can produce ethane would decrease carbon incorporation. Ethane could be generated in photolysis. (3) We have constructed HE-CVD apparatus. Using TMA and hydrogen, high purity Al films without carbon incorporation were deposited on silicon wafers at 250゜C. It was concluded that high quality Al films were deposited by the Hybrid-Excitation CVD at low temperatures. The Hybrid-Excitation CVD method has a potential for deposition of interconnection metals in VLSI technology and for deposition of insulator films.