Patent ID: 8008154
Filing Date: 2011-08-30
Classification: H01L

Abstract:
1. A method of forming an insulating film, the method comprising: forming an insulating film on a substrate; injecting a first impurity into the insulating film using a thermal process under a first set of processing conditions to form a first impurity concentration peak in a lower portion of the insulating film; and injecting a second impurity into the insulating film using the thermal process under a second set of processing conditions, different from the first set of processing conditions, to form a second impurity concentration peak in an upper portion of the insulating film, so that the lower portion of the insulating film and the upper portion of the insulating film have their own maximum impurity concentration values, respectively; wherein the lower portion of the insulating film comprises regions above and below a first region where the first impurity concentration peak occurs that have impurity concentrations less than the first impurity concentration peak, and wherein the upper portion of the insulating film comprises regions above and below a second region where the second impurity concentration peak occurs that have impurity concentrations less than the second impurity concentration peak.