Semiconductor device including backside source/drain contact structure with contact spacer and backside gate contact structure

A semiconductor device comprising:

• a 1st source/drain region;
• a 2nd source/drain region;
• a channel structure connecting the 1st source/drain region to the 2nd source/drain region;
• a gate structure configured to control the channel structure;
• a backside isolation structure at a lower portion of the semiconductor device;
• and
• a backside gate contact structure connected to a bottom surface of the gate structure in the backside isolation structure,
• wherein the backside gate contact structure is misaligned with the bottom surface of the gate structure to be closer to the 2nd source/drain region than the 1st source/drain region,
• wherein a portion of the backside gate contact structure does not contact the bottom surface of the gate structure, and
• wherein the portion of the backside gate contact structure that does not contact the bottom surface of the gate structure contacts a bottom surface of an inner spacer formed between the gate structure and the 1st source/drain region.

A method of manufacturing a semiconductor device, comprising:

• forming a placeholder structure on a bottom surface of a source/drain region;
• forming a contact spacer on the placeholder structure;
• forming a backside gate contact structure on a bottom surface of a gate structure;
• a backside isolation structure at a lower portion of the semiconductor device;
• and
• replacing the placeholder structure with a backside source/drain contact structure such that the backside source/drain contact structure is surrounded by the contact spacer,
• wherein the backside isolation structure is formed between the backside gate contact structure and the contact spacer and isolates the backside gate contact structure from the contact spacer.