Silicon-on-insulator radio frequency device and silicon-on-insulator substrate

A silicon-on-insulator radio frequency device, comprising:

• a silicon-on-insulator substrate, the silicon-on-insulator substrate comprising a high resistivity silicon plate, a top silicon layer and a buried oxide layer between the high resistivity silicon plate and the top silicon layer, wherein at least two active regions are formed in the top silicon layer and a shallow trench isolation structure is formed to separate two adjacent active regions of the at least two active regions;
• and
• a pit formed in the silicon-on-insulator substrate, wherein the number of the pit is at least one, an opening of the pit faces a surface of the shallow trench isolation structure which is away from the buried oxide layer, and the pit extends along a thickness direction of the silicon-on-insulator substrate, penetrates the shallow trench isolation structure, the buried oxide layer and a portion of the high resistivity silicon plate, and is filled with an insulating material.

A silicon-on-insulator substrate, comprising:

• a high resistivity silicon plate, a top silicon layer and a buried oxide layer between the high resistivity silicon plate and the top silicon layer, wherein a pit is formed in the silicon-on-insulator substrate, the number of the pit is at least one, an opening of the pit faces a surface of the high resistivity silicon plate which is away from the buried oxide layer, and the pit extends along a thickness direction of the silicon-on-insulator substrate and penetrates through the high resistivity silicon plate.