Semiconductor device and method of forming the same

A method of forming a semiconductor device, comprising:

• recessing a stack of alternating first semiconductor layers and second semiconductor layers over a substrate to form fin structures, wherein the fin structures comprise fins and nanosheet stacks formed thereon;
• forming an isolation structure on the substrate between the fins;
• forming a separation structure on the isolation structure, wherein the separation structure comprises a body embedded in the nanosheet stacks and a cap protruding from the nanosheet stacks;
• forming a dummy gate stack over the nanosheet stacks and the separation structure;
• removing end portions of the nanosheet stacks and a portion of the cap uncovered by the dummy gate stack to form recesses, wherein a first surface of the cap covered by the dummy gate stack is higher than a second surface of a remaining portion of the cap along a stacking direction of the stack of the alternating first semiconductor layers and the second semiconductor layers;
• and
• forming a gate stack in place of the dummy gate stack.

A method of forming a semiconductor device, comprising:

• forming a first fin structure and a second fin structure extending from a substrate in a first direction, wherein the first fin structure comprises a first fin and a first nanosheet stack formed thereon, and the second fin structure comprises a second fin and a second nanosheet stack formed thereon;
• forming an isolation structure on the substrate and between the first fin and the second fin;
• forming a separator structure on the isolation structure and between the first nanosheet stack and the second nanosheet stack;
• forming a dummy gate structure over and partially covering the separator structure, the first nanosheet stack and the second nanosheet stack;
• removing a portion of the separator structure and portions of the first nanosheet stack and the second nanosheet stack uncovered by the dummy gate structure, wherein a top surface of a portion of the separator structure covered by the dummy gate structure is vertically offset from a top surface of a remaining portion of the separator structure and remaining portions of the first nanosheet stack and the second nanosheet stack, in the first direction at a first height and a second height respectively, wherein a first height is smaller than a second height;
• and
• forming a gate stack in place of the dummy gate stack.