Tokyo Electron Limited

Tokyo Electron Yamanashi Limited

Kazuo Tsuchiya

Hiroshi Nishikawa

Masashi Arasawa

Katsuhiko Ono

A method for SAC etching is provided involving a) etching a Si wafer having a nitride present thereon with a first etching gas containing a first perfluorocarbon and carbon monoxide, and b) etching the resultant Si wafer having an initially etched nitride photoresist thereon with a second etching gas containing a second perfluorocarbon in the substantial absence of carbon monoxide, wherein the etching steps a) and b) are performed at high RF power and low pressure compared to conventional processes to provide higher selectivity etching and a larger process window for SAC etching, as well as the ability to perform SAC etching and island contact etching under the same conditions with high verticality of the island contact and SAC walls.

Method of high selectivity SAC etching

A plasma processing apparatus comprises a first passage opened in a top of suscepter at a peripheral area thereof, a first gas supply source for supplying heat exchange gas into a small clearance between the suscepter and a wafer through the first passage, a first vacuum pump for exhausting the clearance through the first passage, a second passage opened in the top of the suscepter at a center area thereof, a second gas supply source for supplying heat exchange gas into the clearance through the second passage, a second vacuum pump for exhausting the clearance through the second passage, and a controller for controlling the first and second gas supply sources and the first and second vacuum pumps independently of the others in such a way that backpressure caused in the second passage by the second gas supply source and vacuum pump can become lower than backpressure caused in the first passage by the first gas supply source and vacuum pump.

Growing community of inventors

Tokyo, Japan

Kazuo Tsuchiya