Method for forming a DMOS device and a DMOS device

摘要

A method for forming an LDNMOS (1) and LDPMOS (2) in a CMOS process comprises forming the LDNMOS (1) and LDPMOS (2) to a stage where a gate (14) is laid down on a gate oxide layer (12) and a locos (9) is formed over the respective N and P-wells (4) and (5) of the LDNMOS (1) and LDPMOS (2). A P-body (15) is formed in the N-well (4) of the LDNMOS (1) by implanting a boron dopant in two stages, in the first stage at a first tilt angle (theta) of 45° for forming the P-body (15) beneath the gate (14) for determining the source/drain threshold voltage, and subsequently at a second tilt angle (phi) of 7° for extending the P-body (15) downwardly at (25) for determining the punchthrough breakdown voltage of the LDNMOS (1). The formation of an N-body (16) in a P-well (5) of the LDPMOS (2) is similar to the formation of the P-body (15) with the exception that the dopant is a phosphorous dopant.