Patent ID: 6191043
Filing Date: 2001-02-20
Classification: H01L

Abstract:
A method of etching a silicon layer in an inductively coupled plasma etching reactor to form an ultra deep trench, said ultra deep trench having an etch depth of at least 10 .mu.m, said method comprising:providing a semiconductor substrate into said inductively coupled plasma etching reactor, said semiconductor substrate including said silicon layer;flowing an etchant gas chemistry consisting essentially of a helium gas, an O.sub.2 gas, and an argon gas into said inductively coupled plasma etching reactor;striking a plasma using said etchant gas chemistry;providing an SF.sub.6 gas into said inductively coupled plasma etching reactor subsequent to said striking said plasma, wherein a flow ratio of said helium gas to said SF.sub.6 gas is about 350% to about 550%, a flow ratio of O.sub.2 to said SF.sub.6 gas is about 60% to about 90%, and a flow ratio of said argon gas to said SF.sub.6 gas is about 350% to about 550%; andetching said ultra deep trench at least partially through said silicon layer.