摘要:
In one embodiment, the ESD device uses highly doped P and N regions deep within the ESD device to form a zener diode that has a controlled breakdown voltage.
摘要:
A semiconductor device has a driver device (10) in proximity to a power device (12). In making the semiconductor device, an N+ layer (24) is formed on a substrate (22). A portion of the N+ layer is removed, substantially down to the substrate, to provide a layer offset (28) between the driver device area and power device area. An epi region of uniform thickness is formed over the driver device and power device areas. A portion of the epi layer is removed to provide another layer offset (70). An oxide layer (68) of uniform thickness is formed over the epi region. The oxide layer is planarized to remove oxide layer over the N+ layer. An oxide-filled trench (80) is formed between the driver device and the power device. The oxide-filled trench extends down to the oxide layer to isolate the driver device from the power device.
摘要:
A closed cell trench power MOSFET has a trench (54) running in first and second perpendicular directions through a body region (48) and extending into an epitaxial region (46). The trenches meet to form intersections (16). A polysilicon layer (58) is deposited in the trench. A photoresist pattern (60) is formed over the intersections to inhibit removal of the conductive material from the trench in and around the intersection areas. The process of inhibiting removal of the conductive material over the intersection areas of the trench prevents formation of a depression in the polysilicon in and around the intersection which would increase resistivity in the gate region. The goal of preventing formation of depressions in the polysilicon can also be achieved by making the polysilicon thicker on the intersections prior to the etching process and by making the trenches narrower in and around the intersections.