Semiconductor switch device, manufacturing method thereof, and solid-state phase shifter

A solid-state phase shifter, comprising:

• a plurality of semiconductor switch devices, wherein each semiconductor switch device of the plurality of semiconductor switch devices comprises:
• intrinsic layers, wherein each intrinsic layer of the intrinsic layers has a same thickness and a same doping density coefficient as each other intrinsic layer of the intrinsic layers;
• a first semiconductor layer;
• a backside metal layer disposed on a bottom side of the first semiconductor layer opposite to the intrinsic layers, wherein the backside metal layer comprises a titanium nickel aurum material, a titanium platinum aurum material, or a titanium aurum material;
• second semiconductor layers stacked in a sandwich structure and in a one-to-one correspondence with the intrinsic layers, wherein each second semiconductor layer of the second semiconductor layers is stacked on a side of a corresponding intrinsic layer of the intrinsic layers that is away from the first semiconductor layer, wherein the first semiconductor layer, the intrinsic layers, and the second semiconductor layers form a plurality of P-type, intrinsic, N-type (PIN) diodes, and wherein each PIN diode of the plurality of PIN diodes comprises a respective portion of the first semiconductor layer, a respective intrinsic layer of the intrinsic layers, and a respective second semiconductor layer of the second semiconductor layers;
• a plurality of pads disposed on top of the second semiconductor layers away from the intrinsic layers and configured to serve as external electrodes of the semiconductor switch device;
• and
• a first insulation layer embedded in the first semiconductor layer and configured to electrically isolate adjacent intrinsic layers from each other and adjacent second semiconductor layers from each other such that adjacent PIN diodes of the plurality of PIN diodes are electrically isolated from each other,
• wherein the first semiconductor layer is a P+ semiconductor layer and the second semiconductor layers are N+ semiconductor layers.