Patent ID: 7399710
Filing Date: 2008-07-15
Classification: H01L

Abstract:
1. A method of plasma treatment of a semiconductor substrate in a process chamber connected to a vacuum line via a valve, said treatment including a plurality of cycles comprising at least one etching step during which an etching gas is introduced alternating with at least one passivation step during which a passivation gas is introduction into said chamber, the method comprising: (a) defining a reference pressure P (b) fixing a position of the valve during the first etching step, (c) allowing a pressure in the process chamber to stabilize during n cycles, (d) measuring the pressure in the process chamber during the etching step during m cycles, with m at least equal to 2, and calculating an average pressure value P (e) after n+m cycles, correcting the position of the valve to obtain a pressure in the process chamber that approximates the reference pressure value P (f) repeating the steps (c) to (e) until the calculated average pressure P