Lateral diode with multiple spacers

• US 6,967,363 B1
• Filed: 10/01/2003
• Issued: 11/22/2005
• Est. Priority Date: 10/01/2003
• Status: Active Grant

• Current Assignee: Globalfoundries US Incorporated (GlobalFoundries, Inc.)
• Original Assignee: Advanced Micro Devices, Inc.
• Inventors: Buller, James F.
• Primary Examiner(s): Fourson, George
• Assistant Examiner(s): Pham, Thanh V.
• Application Number:
  US10/676,904
• Time in Patent Office: 783 Days
• Field of Search: 257/288, 257/367, 257/E27.051, 257/E29.195, 257/E29.328, 438/237, 438/FOR.415
• US Class Current: 257/288
• CPC Class Codes: H01L 27/0629 in combination with diodes, or resistors, or capacitors
• CPC Class Codes: H01L 27/0814 Diodes only
• CPC Class Codes: H01L 29/7391 Gated diode structures

Abstract

Various circuit devices, including diodes, and methods manufacturing therefor are provided. In one aspect, a method manufacturing is provided that includes forming a gate structure on a semiconductor portion of a substrate. The semiconductor portion has a first conductivity type. First and spacer structures are formed on opposite sides of the gate structure. A first impurity region of a second conductivity type is formed proximate the first spacer structure while the semiconductor portion lateral to the second spacer structure is masked. The first impurity region and the semiconductor portion define a junction. A width of the second spacer structure is reduced while the second spacer structure and the first impurity region are masked. A second impurity region of the first conductivity type is formed in the semiconductor portion proximate the second spacer structure. The method provides a diode with reduced series resistance.

Claims

1. A circuit device, comprising:

a substrate having a semiconductor portion of a first conductivity type;

a gate structure on the semiconductor portion;

first and second spacer structures on opposite sides of the gate structure, the second spacer structure being narrower than the first spacer structure;

a first impurity region of a second conductivity type in the semiconductor portion proximate the first spacer structure, the first impurity region and the semiconductor portion defining a pn junction; and

a second impurity region of the first conductivity type in the semiconductor portion proximate the second spacer structure but in spaced-apart relation to the pn junction.

2. The circuit device of claim 1, wherein the substrate comprises a semiconductor-on-insulator substrate.

3. The circuit device of claim 1, wherein the semiconductor portion comprises silicon.

4. The circuit device of claim 1, wherein the first spacer structures comprises first, second, third and fourth spacers and the second spacer structure comprises fifth and sixth spacers.

5. The circuit device of claim 1, wherein the first conductivity type comprises n-type and the second conductivity type comprises p-type.

6. The circuit device of claim 1, wherein the second impurity region has a lateral boundary positioned closer to the gate structure than the pn junction.

7. The circuit device of claim 1, comprising a conductor coupled to the gate structure and the second impurity region.

8. The circuit device of claim 7, wherein the gate structure is grounded.

9. The circuit device of claim 1, comprising a transistor on the substrate.

10. A diode, comprising:

a substrate having a semiconductor portion with an n-type doping;

a gate structure on the semiconductor portion;

first and second spacer structures on opposite sides of the gate structure, the second spacer structure being narrower than the first spacer structure;

a p-type impurity region in the semiconductor portion proximate the first spacer structure, the p-type impurity region and the semiconductor portion defining a pn junction; and

an n-type impurity region in the semiconductor portion proximate the second spacer structure but in spaced-apart relation to the pn junction.

11. The diode of claim 10, wherein the substrate comprises a semiconductor-on-insulator substrate.

12. The diode of claim 10, wherein the semiconductor portion comprises silicon.

13. The diode of claim 10, wherein the first spacer structures comprises first, second, third and fourth spacers and the second spacer structure comprises fifth and sixth spacers.

14. The diode of claim 10, wherein the second impurity region has a lateral boundary positioned closer to the gate structure than the pn junction.

15. The diode of claim 10, comprising a conductor coupled to the gate structure and the n-type impurity region.

16. The diode of claim 15, wherein the gate structure is grounded.

17. The diode of claim 10, comprising a transistor on the substrate.