Depositing tungsten on a semiconductor substrate

Abstract

Abstract A method of selectively depositing tungsten upon a silicon semiconductor substrate (1), on which a masking film (2) of PSG or SiO₂ is coated and patterned to provide an opening (3) for forming an electrode or wiring therein. On a portion of the substrate in the opening (3), approximately 2000 Angstroms thickness of tungsten (4) is deposited by a CVD method, in which tungsten hexafluoride gas and hydrogen gas are used and the substrate is heated. As a result of this processing, some tungsten nucleii are deposited on the surface of the masking film (2). Before the nucleii form a film, the deposition processing is discontinued and a hydrogen gas is fed in to produce hydrofluoric acid, which etches the surface of the masking film (2), thus to remove the tungsten nucleii thereon. The above-described processings, i.e. deposition and removal of tungsten, are repeated several times until the heights of the deposited tungsten (4+4ʹ+4ʺ..) and the masking film (2) become practically equal, forming a flat surface.

Inventors

• 👤 Yoshimi Fujitsu Limited Shioya
• 👤 Yasushi Fujitsu Limited Oyama
• 👤 Norihisa Fujitsu Limited Tsuzuki
• 👤 Mamoru Fujitsu Limited Maeda
• 👤 Masaaki Fujitsu Limited Ichikawa
• 👤 Fumitake Fujitsu Limited Mieno
• 👤 Shin-Ichi Fujitsu Limited Inoue
• 👤 Yasuo Fujitsu Limited Uo-Ochi
• 👤 Akira Fujitsu Limited Tabuchi
• 👤 Atsuhiro Fujitsu Limited Tsukune
• 👤 Takuya Fujitsu Limited Watanabe
• 👤 Takayuki Fujitsu Limited Ohba

Bibliographic Details