LOW PRESSURE LOW POWER CHLORINE/HYDROGEN CHLORIDE PROCESS FOR SUBMICRON METAL ETCHING

PROBLEM TO BE SOLVED: To make more vertical sidewall shape while reducing the corrosion by a method wherein aluminum and aluminum alloy are anisotropically etched away by RIE using specific low power and pressure. SOLUTION: In the title process, aluminum and aluminum alloy are anisotropically etched away by RIE using low power (not exceeding 350W) and low pressure (not exceeding 15mT). Within an upper layer 14 and a bottom layer 10, the physical etching process called sputtering is performed while in a bulk aluminum layer 12, the chemical process is performed. As for the reaction gas of RIE, chlorine, HCl and inert gas (e.g. nitrogen, argon, helium, etc.) are enumerated. Through these procedures, the corrosion of sidewall and the other problems posed by high power RIE can be solved. Besides, a photoresist 16 can be removed more easily while it is released.