Semiconductor devices and their manufacture

摘要

In a cellular power MOSFET or other semiconductor device, a wide connection across the perimeter of an active device area (120) is replaced with a plurality of narrower conducting fingers (111). The fingers (11) are used as follows in providing a doped edge region (15a) that is required below the connection (110). Dopant (150,151) is implanted at spaces (112) between and beside the fingers (111) and is diffused to form a single continuous region (15a) extending beneath the fingers (111) and at the spaces (112) therebetween. This doped edge region (15a) may be, for example, a deep guard ring in an edge termination of a power MOSFET, or an extension of its channel-accommodating region (15). A trench-gate network (11) of the MOSFET can be connected by the conducting fingers to a gate bond pad and/or field plate (114).