Method and apparatus for suppressing the channeling effect in high energy deep well implantation

摘要

The invention provides an improved well structure for electrically separating n-channel and p-channel MOSFETs. The invention first forms a shallow well in a substrate. A buried amorphous layer is then formed below the shallow well. A deep well is then formed below the buried amorphous layer. The substrate is then subjected to a rapid thermal anneal to recrystallize the buried amorphous layer. The well structure is formed by the shallow well and the deep well. A conventional semiconductor device may then be formed above the well structure. The buried amorphous layer suppresses the channeling effect during the forming of the deep well without requiring a tilt angle.