Sumitomo Precision Products Co., Ltd.

Hiroaki Kouno

Tokiko Kanayama

Yoshiyuki Nozawa

Kazuo Kasai

A method for etching a silicon substrate is presented in which fast etching speed and etching structures with smooth and perpendicular wall surfaces are achieved. In the etching step, a constant electric power is applied to the silicon substrate to provide a bias potential. Using a mixture of SFgas and fluorocarbon gas, there is a step mainly for the progression of dry etching of the etching ground surface. Similarly, using a mixture gas, there is a step mainly for forming a protective layer on the structure surfaces which are perpendicular with respect to the etching ground surface. These two steps are repeated one after the other. In the step for dry etching, the mixture gas is 5&#x2013;12 volume of fluorocarbon gas with respect to 100 volume SFgas. The mixture gas in the protective film formation step is a mixture of 2&#x2013;5 volume of SFgas with respect to 100 volume fluorocarbon gas.

Method for etching of a silicon substrate and etching apparatus

A cleaning method and an etching method for removing, by cleaning grease components and silicon micro pieces hard to remove, used for an apparatus and a carrier for manufacturing a semiconductor wafer or a semiconductor device. Matters to be removed are brought into contact with XeFgas produced by sublimation in a vacuum atmosphere to decompose and gasify the grease components and to remove silicon pieces by etching. If a trace of residual water is left in the vacuum atmosphere before the cleaning, the HO reacts with XeF, so that HF is produced. Therefore, for example, the native oxide SiOformed on the silicon pieces can be removed, and XeFcan directly react with silicon, thereby enabling etching. The cleaning and etching speeds are extremely accelerated.

Cleaning method and etching method

A cleaning method for removing fats, oils, and silicon small particles, which are conventionally difficult to remove, adhering to devices and carriers used to manufacture a semiconductor wafer or a semiconductor device. An etching method is also disclosed. XeFgas produced by sublimation is made to contact with an object to be cleaned in a vacuum atmosphere so as to decompose and gasify the oils and fats and to remove silicon small particles by etching. Prior to the cleaning, when a trace amount of residual water is left in the vacuum atmosphere, HO reacts with XeF, and HF is produced. For example, a native oxide SiOformed on the surface of silicon small particles can be removed, and XeFdirectly reacts with silicon, therby enabling etching. The cleaning etching rates are extremely high.

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Yawata, Japan

Hiroaki Kouno