THERMAL CONDUCTIVITY ENHANCED SEMICONDUCTOR STRUCTURES AND FABRICATION PROCESSES

摘要

PURPOSE: A thermal conductivity enhanced semiconductor structure is provided to improve heat dissipation in semiconductor devices and electrostatic discharge(ESD) robustness. CONSTITUTION: Starting with an SOI wafer(12, 14, 16) as before, a layer of silicon nitride(22) is deposited to a thickness approximating the desired final thickness of the gate polysilicon of an active device, generally in the range of 500 to 3000 Angstroms (which is large relative to gate insulator thickness). A photoresist mask layer(26) is then deposited and patterned with openings only at the locations of the thermal plug(20). The nitride layer and wafer are then etched to the back side bulk silicon, as before. The resist is then removed and another resist mask formed with openings at the gate active regions and the nitride layer is etched through to the SOI wafer surface of the active silicon layer.