Integration methods to fabricate internal spacers for nanowire devices
A nanowire device having a plurality of internal spacers and a method for forming said internal spacers are disclosed. In an embodiment, a semiconductor device comprises a nanowire stack disposed above a substrate, the nanowire stack having a plurality of vertically-stacked nanowires, a gate structure wrapped around each of the plurality of nanowires, defining a channel region of the device, the gate structure having gate sidewalls, a pair of source/drain regions on opposite sides of the channel region; and an internal spacer on a portion of the gate sidewall between two adjacent nanowires, internal to the nanowire stack. In an embodiment, the internal spacers are formed by depositing spacer material in dimples etched adjacent to the channel region. In an embodiment, the dimples are etched through the channel region. In another embodiment, the dimples are etched through the source/drain region.
1. An integrated circuit structure, comprising:
a semiconductor fin;
a first gate stack portion above the semiconductor fin, the first gate stack portion comprising a gate dielectric material on a top surface, on a bottom surface and on sidewalls of a gate electrode material;
a nanowire on the first gate stack portion; a pair of insulative spacers beneath the nanowire, wherein a first of the pair of insulative spacers is in contact with a first side of the first gate stack portion, and a second of the pair of insulative spacers is in contact with a second side of the first gate stack portion; and
a second gate stack portion on the nanowire, the second gate stack portion comprising a gate dielectric material on a bottom surface and on sidewalls of a gate electrode material;
a first source or drain structure laterally adjacent to and in direct physical contact with the first of the pair of insulative spacers and a first end of the nanowire; and
a second source or drain structure laterally adjacent to and in direct physical contact with the second of the pair of insulative spacers and a second end of the nanowire.
2. The integrated circuit structure of claim 1 , wherein the gate dielectric material of the second gate stack portion is further on a top surface of the gate electrode material of the second gate stack portion.
3. The integrated circuit structure of claim 2 , further comprising:
a second nanowire on the second gate stack portion;
a second pair of insulative spacers beneath the second nanowire, wherein a first of the second pair of insulative spacers is in contact with a first side of the second gate stack portion, and a second of the second pair of insulative spacers is in contact with a second side of the second gate stack portion; and
a third gate stack portion on the second nanowire, the third gate stack portion comprising a gate dielectric material on a bottom surface and on sidewalls of a gate electrode material.
4. The integrated circuit structure of claim 3 , wherein the gate dielectric material of the third gate stack portion is further on a top surface of the gate electrode material of the third gate stack portion.
5. The integrated circuit structure of claim 3 , wherein the first source or drain structure is further laterally adjacent to and in contact with the first of the second pair of insulative spacers and a first end of the second nanowire, and wherein the second source or drain structure is further laterally adjacent to and in contact with the second of the second pair of insulative spacers and a second end of the second nanowire.
6. The integrated circuit structure of claim 5 , wherein the first and second source or drain structures comprise a homogeneous semiconductor material.
7. The integrated circuit structure of claim 6 , wherein the homogeneous semiconductor material is doped.
8. The integrated circuit structure of claim 3 , wherein the pair of insulative spacers and the second pair of insulative spacers are connected to form a pair of continuous spacers.
9. The integrated circuit structure of claim 8 , wherein the nanowire and the second nanowire extend through the pair of continuous spacers.
10. The integrated circuit structure of claim 9 , wherein the first and second source or drain structures comprise a portion of the nanowire and the second nanowire that extend through the pair of continuous spacers.
11. The integrated circuit structure of claim 8 , wherein the nanowire and the second nanowire do not extend through the pair of continuous spacers.
12. The integrated circuit structure of claim 1 , wherein the first and second gate stack portions are connected to form a continuous gate stack.
13. The integrated circuit structure of claim 1 , wherein the nanowire is a silicon nanowire.
14. A computing device, comprising:
a board; and
a component coupled to the board, the component including an integrated circuit structure, comprising:
a semiconductor fin;
a first gate stack portion above the semiconductor fin, the first gate stack portion comprising a gate dielectric material on a top surface, on a bottom surface and on sidewalls of a gate electrode material;
a nanowire on the first gate stack portion;
a pair of insulative spacers beneath the nanowire, wherein a first of the pair of insulative spacers is in contact with a first side of the first gate stack portion, and a second of the pair of insulative spacers is in contact with a second side of the first gate stack portion; and
a second gate stack portion on the nanowire, the second gate stack portion comprising a gate dielectric material on a bottom surface and on sidewalls of a gate electrode material;
a first source or drain structure laterally adjacent to and in direct physical contact with the first of the pair of insulative spacers and a first end of the nanowire; and
a second source or drain structure laterally adjacent to and in direct physical contact with the second of the pair of insulative spacers and a second end of the nanowire.
15. The computing device of claim 14 , further comprising:
a memory coupled to the board.
16. The computing device of claim 14 , further comprising:
a communication chip coupled to the board.
17. The computing device of claim 14 , further comprising: a camera coupled to the board.
18. The computing device of claim 14 , wherein the component is a packaged integrated circuit die.
19. The computing device of claim 14 , wherein the component is selected from the group consisting of a processor, a communications chip, and a digital signal processor.
20. The computing device of claim 14 , wherein the computing device is selected from the group consisting of a mobile phone, a laptop, a desk top computer, a server, and a set-top box.
21. An integrated circuit structure, comprising:
a semiconductor fin;
a first gate stack portion above the semiconductor fin, the first gate stack portion comprising a gate dielectric material on a top surface, on a bottom surface and on sidewalls of a gate electrode material;
a nanowire on the first gate stack portion;
a pair of insulative spacers beneath the nanowire, wherein a first of the pair of insulative spacers is in contact with a first side of the first gate stack portion, and a second of the pair of insulative spacers is in contact with a second side of the first gate stack portion; and
a second gate stack portion on the nanowire, the second gate stack portion comprising a gate dielectric material on a bottom surface, on a top surface, and on sidewalls of a gate electrode material;
a second nanowire on the second gate stack portion;
a second pair of insulative spacers beneath the second nanowire, wherein a first of the second pair of insulative spacers is in contact with a first side of the second gate stack portion, and a second of the second pair of insulative spacers is in contact with a second side of the second gate stack portion;
a third gate stack portion on the second nanowire, the third gate stack portion comprising a gate dielectric material on a bottom surface and on sidewalls of a gate electrode material;
a first source or drain structure laterally adjacent to and in contact with the first of the pair of insulative spacers and a first end of the nanowire; and
a second source or drain structure laterally adjacent to and in contact with the second of the pair of insulative spacers and a second end of the nanowire.