Patent ID: 8829613

Claim:
A semiconductor device, comprising: a semiconductor substrate; a first field plate area defined over said substrate, a second field plate area defined over said substrate adjacent to said first field plate area, and a third field plate area defined over said semiconductor substrate adjacent to said second field plate area; a first dielectric layer disposed over said semiconductor substrate, of which at least a portion of said first dielectric layer is absent in at least one of said first field plate area, said second field plate area and said third field plate area; a second dielectric layer disposed over said first dielectric layer and over said semiconductor substrate; and a stepped field plate disposed over said first dielectric layer and said second dielectric layer in said first field plate area, said second field plate area and said third field plate area, in which: a capacitance per unit area in said first field plate area between said stepped field plate and said semiconductor substrate is at least 10 percent more than a capacitance per unit area in said second field plate area between said stepped field plate and said semiconductor substrate; and a capacitance per unit area in said second field plate area between said stepped field plate and said semiconductor substrate is at least 10 percent more than a capacitance per unit area in said third field plate area between said stepped field plate and said semiconductor substrate.