Patent ID: 9018075
Filing Date: 2015-04-28
Classification: H01L

Abstract:
1. A plasma processing method, for forming trenches by plasma-etching a silicon substrate with a mask having a minimum opening width of a trench pattern of 20 nm or less, comprising: a nitride-film forming step to form a nitride film; a first silicon-etching step to plasma-etch the silicon substrate using the mask, after the nitride-film forming step; an oxide-film forming step, to form an oxide film on bottom surfaces of the silicon substrate being plasma-etched to a given depth, using a plasma with RF power of 0 W supplied to a sample stage on which the silicon substrate is mounted, after the silicon substrate is plasma-etched to the given depth by repeating the nitride-film forming step and the first silicon-etching step; and a second silicon-etching step to plasma-etch the silicon substrate, after the oxide-film forming step.