Semiconductor devices using fully-depleted silicon-on-insulator (fdsoi) and methods for forming the same

A semiconductor device, comprising:

• a semiconductor layer;
• an insulating layer stacked on the semiconductor layer along a first direction;
• a first transistor comprising a first gate structure and a first semiconductor body, wherein the first semiconductor body is in contact with the insulating layer;
• and
• a second transistor extending into the semiconductor layer along the first direction, wherein the second transistor comprises a second gate structure and a second semiconductor body, the second gate structure comprises a dielectric layer in contact with the second semiconductor body, and a size of the dielectric layer of the second gate structure along the first direction is similar to or same as a size of the insulating layer along the first direction.

A method of forming a semiconductor device, comprising:

• forming a semiconductor structure comprising a first semiconductor layer and an insulating layer stacked on the first semiconductor layer along a first direction;
• forming a first transistor of the semiconductor device, wherein the first transistor comprises a first gate structure and a first semiconductor body, and the first semiconductor body is in contact with a first portion of the insulating layer;
• and
• forming a second transistor of the semiconductor device, wherein the second transistor comprises a second gate structure and a second semiconductor body, the second gate structure comprises a second portion of the insulating layer, the second semiconductor body comprises a portion of the first semiconductor layer, the second portion of the insulating layer is aligned with the first portion of the insulating layer along a second direction perpendicular to the first direction.