(Invited) Hot Carrier Reliability of High Voltage HVMOSFETs in BCD (Bipolar-CMOS-DMOS) Technology

Abstract

This paper discusses three important practical issues in hot carrier (HC) reliability of Laterally Diffused MOSFETs (LDMOSFETs) or high voltage MOSFET (HVMOSFETs) in Bipolar-CMOS-DMOS (BCD) technology. One of the main reliability issues encountered during development of the LDMOSFET or HVMOSFET is optimizing the trade-offs between specific on-resistance (Rdson) and hot carrier (HC) degradation. We developed a new LDMOS/HVMOS structure in which the HC degradation has been significantly reduced without sacrificing the Rdson. The second issue is how to reduce HC degradation in LDMOS due to plasma reduced charge in Back-End-Of-Line (BEOL). We demonstrate a modified SiN barrier layer which can improve device hot carrier performance. A third issue is that self heating, caused by HC stress in packaged LDMOS and HVMOS devices, significantly affects the HC degradation characteristics. A method is proposed to eliminate the influence of the self heating effect on HC measurement.