NOVEL SCHOTTKY DIODE FOR HIGH SPEED AND RADIO FREQUENCY APPLICATION

• US 20090283851A1
• Filed: 05/15/2008
• Published: 11/19/2009
• Est. Priority Date: 05/15/2008
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Chen, Shou-Mao
• Granted Patent: US 7,649,237 B2
• Time in Patent Office: Days
• US Class Current: 257/475
• CPC Class Codes: H01L 27/0814 Diodes only
• CPC Class Codes: H01L 27/095 the components being Schottky barrier gate field-effect transistors
• CPC Class Codes: H01L 29/1604 Amorphous materials
• CPC Class Codes: H01L 29/161 including two or more of the elements provided for in group H01L29/16 , e.g. alloys H01L29/1604 takes precedence
• CPC Class Codes: H01L 29/20 including, apart from doping materials or other impurities, only AIIIBV compounds
• CPC Class Codes: H01L 29/47 Schottky barrier electrodes H01L29/435 takes precedence
• CPC Class Codes: H01L 29/4916 the conductor material next to the insulator being a silicon layer, e.g. polysilicon doped with boron, phosphorus or nitrogen H01L29/4908, H01L29/4983 take precedence
• CPC Class Codes: H01L 29/4925 with a multiple layer structure, e.g. several silicon layers with different crystal structure or grain arrangement with only a vertical doping structure or vertical doping variation H01L29/4916
• CPC Class Codes: H01L 29/517 the insulating material comprising a metallic compound, e.g. metal oxide, metal silicate H01L29/518 takes precedence
• CPC Class Codes: H01L 29/518 the insulating material containing nitrogen, e.g. nitride, oxynitride, nitrogen-doped material
• CPC Class Codes: H01L 29/66143 Schottky diodes
• CPC Class Codes: H01L 29/66356 Gated diodes, e.g. field controlled diodes [FCD], static induction thyristors [SITh], field controlled thyristors [FCTh]
• CPC Class Codes: H01L 29/7391 Gated diode structures
• CPC Class Codes: H01L 29/872 Schottky diodes

Abstract

A semiconductor diode that eliminates leakage current and reduces parasitic resistance is disclosed. The semiconductor diode comprises a semiconductor substrate; a semiconductor layer disposed on the semiconductor substrate, wherein the semiconductor layer includes a first dopant and a first well with a Schottky region; and a polysilicon device positioned above the semiconductor layer and adjacent to the first well with the Schottky region.

Claims

1. A semiconductor diode comprising:

a semiconductor substrate;

a semiconductor layer disposed on the semiconductor substrate, wherein the semiconductor layer includes a first dopant and a first well with a Schottky region; and

a polysilicon device positioned above the semiconductor layer and adjacent to the first well with the Schottky region.

2. The semiconductor diode of claim 1 further comprising:

a first node coupled to the first well with the Schottky region;

the semiconductor layer having a second well with a second dopant, the second dopant being of a common conductivity type as the first dopant;

a second node coupled to the second well; and

a third node coupled to the polysilicon device.

3. The semiconductor diode of claim 2 wherein the polysilicon device is positioned between the first well and the second well.

4. The semiconductor diode of claim 2 wherein the first well with the Schottky region is of a common conductivity type as the first dopant and the second dopant.

5. The semiconductor diode of claim 2 wherein the conductivity type for the first dopant, second dopant, and first well with the Schottky region is n-type.

6. The semiconductor diode of claim 2 wherein there is a direct path through the semiconductor layer between the connection with the first node and the connection with the second node, without an intervening non-conductive region.

7. The semiconductor diode of claim 1 wherein the first well with the Schottky region includes a light n-type low threshold voltage (LVT) dopant or a light n-type non-voltage threshold (non-VT) dopant.

8. The semiconductor diode of claim 2 wherein the second well includes a lightly doped drain (LDD) portion.

9. The semiconductor diode of claim 2 wherein the first node includes a high-potential terminal, the second node includes a low-potential terminal, and the third node includes either a floating terminal or a voltage-biased terminal.

10. The semiconductor diode of claim 2, wherein the polysilicon device is electrically connected to the first well with the Schottky region in parallel, the third node coupled to the polysilicon device being electrically connected to the first node coupled to the first well.

11. The semiconductor diode of claim 2, wherein the polysilicon device is electrically connected to the first well with the Schottky region in series, the third node being coupled to the polysilicon device, the first node being coupled to the first well, and the second node being electrically isolated from the polysilicon device.

12. The semiconductor diode of claim 11, wherein the third node includes a low-potential terminal, and the first node includes a high-potential terminal.

20. A semiconductor diode array comprising a plurality of semiconductor diodes, wherein the semiconductor diodes include:

a semiconductor substrate;

a semiconductor layer disposed on the semiconductor substrate, the semiconductor layer including a first dopant, a first well with a Schottky region, and a second well with a second dopant, wherein a first node is coupled to the first well with the Schottky region and a second node is coupled to the second well; and

a polysilicon device positioned between the first well and the second well, wherein a third node is coupled to the polysilicon device.

21. A semiconductor diode comprising:

a semiconductor substrate;

a semiconductor layer disposed on the semiconductor substrate, wherein the semiconductor layer includes a first dopant and a first well with a Schottky region; and

an isolation region replacement element positioned above the semiconductor layer and adjacent to the first well with the Schottky region.

13. The semiconductor diode of claim 21, wherein the isolation region replacement element positioned above the semiconductor layer and adjacent to the first well with the Schottky region comprises a resist protection oxide region.

14. The semiconductor diode of claim 13 further comprising:

a first node coupled to the first well with a Schottky region;

the semiconductor layer having a second well with a second dopant, the second dopant being of a common conductivity type as the first dopant; and

a second node coupled to the second well.

15. The semiconductor diode of claim 14 wherein the resist protection oxide region is positioned between the first well and the second well.

16. The semiconductor diode of claim 14 wherein the first well with the Schottky region is of a common conductivity type as the first dopant and the second dopant.

17. The semiconductor diode of claim 14 wherein the conductivity type for the first dopant, second dopant, and first well with the Schottky region is n-type.

18. The semiconductor diode of claim 14 wherein there is a direct path through the semiconductor layer between the connection with the first node and the connection with the second node, without an intervening non-conductive region.

19. The semiconductor diode of claim 13 wherein the first well with the Schottky region includes a light n-type low threshold voltage (LVT) dopant or a light n-type non-voltage threshold (non-VT) dopant.