MIS (Metal-Insulator-Semiconductor) contact structures for semiconductor devices
An MIS contact structure comprises a layer of semiconductor material, a layer of insulating material having a contact opening formed therein, a layer of contact insulating material having substantially vertically oriented portions and a substantially horizontally oriented portion, the vertically oriented portions of the layer of contact insulating material contacting a portion, but not all, of the sidewalls of the contact opening and the horizontally oriented portion of the layer of contact insulating material contacting the semiconductor layer. A conductive material is positioned on the layer of contact insulating material within the contact opening, the conductive material layer having vertically oriented portions and a horizontally oriented portion and a conductive contact positioned in the contact opening that contacts the uppermost surfaces of the conductive material layer and the layer of contact insulating material.
1. A device, comprising:
a layer of semiconductor material;
a layer of insulating material having a contact opening formed therein positioned above said layer of semiconductor material, said contact opening having sidewalls;
a layer of contact insulating material having substantially vertically oriented portions and a substantially horizontally oriented portion positioned between said substantially vertically oriented portions of said layer of contact insulating material, wherein said substantially vertically oriented portions of said layer of contact insulating material contact a portion, but not all, of said sidewalls of said contact opening and wherein said substantially horizontally oriented portion of said layer of contact insulating material contacts said semiconductor layer;
a conductive material layer positioned on said layer of contact insulating material within said contact opening, said conductive material layer having substantially vertically oriented portions and a substantially horizontally oriented portion positioned between said substantially vertically oriented portions of said conductive material layer, wherein an uppermost surface of said conductive material layer and an uppermost surface of said layer of contact insulating material are positioned at approximately a same level within said contact opening; and
a conductive contact positioned in said contact opening that contacts said uppermost surfaces of said conductive material layer and said layer of contact insulating material.
2. The device of claim 1 , wherein said semiconductor layer comprises one of a source/drain region, a gate structure or a resistor.
3. The device of claim 1 , wherein said layer of contact insulating material is comprised of one of silicon nitride, a high-k insulating material (k value of 10 or greater) or silicon oxynitride.
4. The device of claim 1 , wherein said conductive material layer is comprised of one of a metal, a metal alloy or polysilicon.
5. The device of claim 1 , wherein said layer of contact insulating material and said conductive material layer define a generally U-shaped structure that occupies less than an entirety of a depth of said contact opening.
6. The device of claim 1 , wherein a portion of said conductive contact is positioned above said uppermost surface of said conductive material layer and said uppermost surface of said layer of contact insulating material.
7. The device of claim 6 , wherein said conductive material layer defines a recess positioned between said substantially vertically oriented portions and above said substantially horizontally oriented portion of said conductive material layer, and wherein a portion of said conductive contact is positioned within said recess.
8. The device of claim 1 , wherein said same level of said uppermost surface of said conductive material layer and said uppermost surface of said layer of contact insulating material is positioned approximately 10-40 nm above an upper surface of said layer of semiconductor material.
9. The device of claim 1 , wherein said contact insulating material has a thickness of about 0.5-2 nm and said conductive material layer has a thickness of about 2-8 nm.
10. The device of claim 1 , wherein said contact opening, when viewed from above, has one of a generally square configuration, a generally circular configuration or a line-type configuration.
11. A device, comprising:
a layer of semiconductor material;
a layer of insulating material having a contact opening formed therein positioned above said layer of semiconductor material, said contact opening having sidewalls;
a layer of contact insulating material having substantially vertically oriented portions and a substantially horizontally oriented portion positioned between said substantially vertically oriented portions of said layer of contact insulating material, wherein said substantially vertically oriented portions of said layer of contact insulating material contact a portion, but not all, of said sidewalls of said contact opening and wherein said substantially horizontally oriented portion of said layer of contact insulating material contacts said semiconductor layer;
a conductive material layer positioned on said layer of contact insulating material within said contact opening, said conductive material layer having substantially vertically oriented portions and a substantially horizontally oriented portion positioned between said substantially vertically oriented portions of said conductive material layer, wherein an uppermost surface of said conductive material layer and an uppermost surface of said layer of contact insulating material are positioned at approximately a same level within said contact opening, wherein said layer of contact insulating material and said conductive material layer occupies less than an entirety of a depth of said contact opening; and
a conductive contact positioned in said contact opening that contacts said uppermost surfaces of said conductive material layer and said layer of contact insulating material, wherein a portion of said conductive contact is positioned above said uppermost surface of said conductive material layer and said uppermost surface of said layer of contact insulating material.
12. The device of claim 11 , wherein said semiconductor layer comprises one of a source/drain region, a gate structure or a resistor, said layer of contact insulating material is comprised of one of silicon nitride, a high-k insulating material (k value of 10 or greater) or silicon oxynitride, and said conductive material layer is comprised of one of a metal, a metal alloy or polysilicon.
13. The device of claim 12 , wherein said layer of contact insulating material and said conductive material layer define a generally U-shaped structure.
14. The device of claim 11 , wherein said conductive material layer defines a recess positioned between said substantially vertically oriented portions and above said substantially horizontally oriented portion of said conductive material layer, and wherein a portion of said conductive contact is positioned within said recess.
15. The device of claim 14 , wherein said same level of said uppermost surface of said conductive material layer and said uppermost surface of said layer of contact insulating material is positioned approximately 10-40 nm above an upper surface of said layer of semiconductor material.
16. The device of claim 15 , wherein said contact insulating material has a thickness of about 0.5-2 nm and said conductive material layer has a thickness of about 2-8 nm.
17. The device of claim 13 , wherein said contact opening, when viewed from above, has one of a generally square configuration, a generally circular configuration or a line-type configuration.