Silicon-on-insulator chip having an isolation barrier for reliability

• US 20020043686A1
• Filed: 06/11/2001
• Published: 04/18/2002
• Est. Priority Date: 01/20/1998
• Status: Active Grant

• Current Assignee: GlobalFoundries, Inc.
• Original Assignee: International Business Machines Corporation
• Inventors: Schepis, Dominic J., Bolam, Ronald J., Kulkarni, Subhash B.
• Granted Patent: US 6,492,684 B2
• Time in Patent Office: Days
• US Class Current: 257/349
• CPC Class Codes: H01L 21/743 Making of internal connections, substrate contacts
• CPC Class Codes: H01L 21/76264 SOI together with lateral isolation, e.g. using local oxidation of silicon, or dielectric or polycristalline material refilled trench or air gap isolation regions, e.g. completely isolated semiconductor islands
• CPC Class Codes: H01L 21/76283 Lateral isolation by refilling of trenches with dielectric material
• CPC Class Codes: H01L 27/1203 the substrate comprising an insulating body on a semiconductor body, e.g. SOI three-dimensional layout H01L27/0688
• CPC Class Codes: H01L 29/66772 Monocristalline silicon transistors on insulating substrates, e.g. quartz substrates H01L29/66666 takes precedence; thin film FinFETs H01L29/66795
• CPC Class Codes: H01L 29/78636 with supplementary region or layer for improving the flatness of the device
• CPC Class Codes: H01L 29/78648 arranged on opposing sides of the channel

Abstract

An SOI chip having an isolation barrier. The SOI chip includes a substrate, an oxide layer deposited on the substrate, and a silicon layer deposited on the oxide layer. A gate is deposited above the silicon layer. A first metal contact is deposited above the gate to form an electrical contact with the gate. Second and third metal contacts are deposited to form electrical contacts with the silicon layer. The isolation barrier extends through the silicon layer and the oxide layer, and partially into the substrate, to block impurities in the oxide layer outside the isolation barrier from diffusing into the oxide layer inside the isolation barrier. The isolation barrier surrounds the gate, the first metal contact, the second metal contact, and the third metal contact—which define an active chip area inside the isolation barrier. A method of manufacturing the SOI chip is also disclosed.

Claims

1. A silicon-on-insulator (SOI) semiconductor chip comprising:

a peripheral edge;

a substrate;

an oxide layer on the substrate;

a silicon layer on the oxide layer;

an active area;

an isolation barrier including a groove;

(a) being disposed slightly inward of the peripheral edge of the chip,

(b) extending through the silicon layer and through the oxide layer and partially into the substrate to prohibit impurities in the oxide layer outside the isolation barrier from diffusing into the oxide layer inside the isolation barrier, and

(c) surrounding completely the active area of the chip, and

a passivation layer on the silicon layer and extending to the groove.

2. The SOI chip according to claim 1 wherein the active area of the chip includes a gate located on the silicon layer, a gate metal contact deposited above and forming an electrical contact with the gate, and at least one metal contact deposited above and forming an electrical contact with the silicon layer.

3. The SOI chip according to claim 1 wherein the passivation layer is selected from the group consisting of silicon nitride, polysilicon, oxide, and nitride.

4. The SOI chip according to claim 1 further comprising a barrier material located (i) over the passivation layer on the silicon layer, and (ii) in the groove presenting an additional barrier to impurities in the oxide layer outside the groove from diffusing into the oxide layer inside the groove.

5. The SOI chip according to claim 4 wherein the barrier material is dielectric.

6. The SOI chip according to claim 5 wherein the barrier material is selected from the group consisting of phosphosilicate glass (PSG), BPSG, nitride and oxide.

7. The SOI chip according to claim 1 further comprising the passivation layer on the silicon layer and in the groove.

8. The SOI chip according to claim 7 wherein the passivation layer is selected from the group of silicon nitride, polysilicon, oxide, and nitride.

9. The SOI chip according to claim 7 further comprising an oxide located in the groove and over the passivation layer which is on the silicon layer and in the groove.

10. The SOI chip according to claim 7 further comprising a barrier material located on the passivation layer, over the silicon layer and in the groove, presenting an additional barrier to impurities in the oxide layer outside the groove from diffusing into the oxide layer inside the groove.

11. The SOI chip according to claim 10 wherein the barrier material is dielectric.

12. The SOI chip according to claim 11 wherein the barrier material is selected from the group consisting of phosphosilicate glass (PSG), BPSG, and nitride.

13. The SOI chip according to claim 10 further comprising an oxide located in the groove and over the barrier material and the passivation layer which are in the groove.

14. The SOI chip according to claim 1 wherein the groove is defined by side walls and an open bottom, the SOI chip further comprising the passivation layer on the silicon layer and the side walls of the groove with the bottom of the groove devoid of the passivation layer.

15. The SOI chip according to claim 14 wherein the passivation layer is selected from the group consisting of silicon nitride, polysilicon, oxide, and nitride.

16. The SOI chip according to claim 14 further comprising a fill material deposited in the groove adjacent the passivation layer on the side walls of the groove and contacting the substrate through the open bottom of the groove.

17. The chip according to claim 16 wherein the fill material is polysilicon.

18. The SOI chip according to claim 17 wherein the polysilicon fill material is doped conductive, forming an electrical contact with the substrate.

19. The SOI chip according to claim 18 further comprising a metal contact extending from the doped conductive fill material and forming an electrical contact with substrate.

20. The SOI chip according to claim 1 wherein the groove has a width of about 1-2 microns.

21. A silicon-on-insulator (SOI) semiconductor chip comprising:

a peripheral edge;

a substrate;

an oxide layer on the substrate;

a silicon layer on the oxide layer;

a passivation layer on the silicon layer;

an active area including a gate located above the silicon layer, a gate metal contact located above and forming an electrical contact with the gate, and at least one metal contact located above and forming an electrical contact with the silicon layer;

an isolation barrier, including a groove;

(a) being disposed slightly inward of the peripheral edge of the chip,

(b) extending through the silicon layer and through the oxide layer and partially into the substrate to prohibit impurities in the oxide layer outside the isolation barrier from diffusing into the oxide layer inside the isolation barrier, and

(c) surrounding completely the active area of the chip;

a barrier material located (I) over the passivation layer on the silicon layer, and (ii) in the groove, presenting an additional barrier to impurities in the oxide layer outside the groove from diffusing into the oxide layer inside the groove.

22. A silicon-on-insulator (SOI) semiconductor chip comprising:

a peripheral edge;

a substrate;

an oxide layer on the substrate;

a silicon layer on the oxide layer;

a passivation layer on the silicon layer;

an active area;

an isolation barrier, including a groove;

(a) being disposed slightly inward of the peripheral edge of the chip,

(b) extending through the silicon layer and through the oxide layer and partially into the substrate to prohibit impurities in the oxide layer outside the isolation barrier from diffusing into the oxide layer inside the isolation barrier, and

(c) surrounding completely the active area of the chip;

a barrier material located;

(a) over the passivation layer on the silicon layer, and

(b) in the groove, presenting an additional barrier to impurities in the oxide layer outside the groove from diffusing into the oxide layer inside the groove.

23. The SOI chip according to claim 22 wherein the passivation layer is selected from the group consisting of silicon nitride, polysilicon, oxide, and nitride.

24. The SOI chip according to claim 22 wherein the barrier material is dielectric.

25. The SOI chip according to claim 24 wherein the barrier material is selected from the group consisting of phosphosilicate glass (PSG), BPSG, nitride and oxide that prevents impurities in said oxide layer outside said isolation barrier from diffusing into said oxide layer inside said isolation barrier.

26. The SOI chip according to claim 22 wherein the groove has a width of about 1-2 microns.

27. The SOI chip according to claim 22 wherein the groove in the isolation barrier extends through the passivation layer.

29. The SOI chip according to claim 28 wherein the passivation layer is selected from the group consisting of silicon nitride, polysilicon, oxide, and nitride.

30. The SOI chip according to claim 28 wherein the fill material is polysilicon.

31. The SOI chip according to claim 29 wherein the barrier material is polysilicon.

32. The SOI chip according to claim 31 wherein the barrier material is dielectric.

33. The SOI chip according to claim 32 wherein the barrier material is selected from the group consisting of phosphosilicate glass (PSG), BPSG, nitride and oxide that prevents impurities in said oxide layer outside said isolation barrier from diffusing into said oxide layer inside said isolation barrier.

34. The SOI chip according to claim 31 further comprising an oxide located in the groove and over the barrier material and the passivation layer which are in the groove.

35. The SOI chip according to claim 22 wherein the barrier material is conductive.

28. A silicon-on-insulator (SOI) semiconductor chip comprising:

a peripheral edge;

a substrate;

an oxide layer on the substrate;

a silicon layer on the oxide layer;

an active area;

an isolation barrier;

(a) including a groove defined by side walls and an open bottom,

(b) being disposed slightly inward of the peripheral edge of the chip,

(c) extending through the silicon layer and through the oxide layer and partially into the substrate to prohibit impurities in the oxide layer outside the isolation barrier from diffusing into the oxide layer inside the isolation barrier, and

(d) surrounding completely the active area of the chip;

a passivation layer on the silicon layer and the side walls of the groove with the bottom of the groove devoid of the passivation layer;

a doped conductive fill material located in the groove adjacent the passivation layer on the sidewalls of the groove forming an electrical contact with the substrate and contacting the substrate through the open bottom of the groove; and

a metal contact extending from the doped conductive fill material and forming an electrical contact with the doped conductive fill material.

36. A silicon-on-insulator (SOI) semiconductor chip comprising:

a peripheral edge;

a substrate;

an oxide layer on the substrate;

a silicon layer on the oxide layer;

an active area;

an isolation barrier, including a groove;

(a) being disposed slightly inward of the peripheral edge of the chip,

(b) extending through the silicon layer and through the oxide layer and partially into the substrate to prohibit impurities in the oxide layer outside the isolation barrier from diffusing into the oxide layer inside the isolation barrier, and

(c) surrounding completely the active area of the chip;

a passivation layer on the silicon layer and in the groove; and

a barrier material located in the passivation layer, over the silicon layer, and in the groove presenting an additional barrier to impurities in the oxide layer outside the groove from diffusing into the oxide layer inside the groove.

37. A silicon-on-insulator (SOI) semiconductor chip comprising:

a peripheral edge;

a substrate;

an oxide layer on the substrate;

a silicon layer on the oxide layer;

an active area;

an isolation barrier, including a groove;

(a) being disposed slightly inward of the pheriphal edge of the chip,

(b) extending through the silicon layer and through the oxide layer and partially into the substrate to prohibit impurities in the oxide layer outside the isolation barrier from diffusing into the oxide layer inside the isolation barrier, and

(c) surrounding completely the active area of the chip.

38. A silicon-on-insulator (SOI) semiconductor chip comprising:

a peripheral edge;

a substrate;

an oxide layer on the substrate;

a silicon layer on the oxide layer;

an active area;

an isolation barrier, including a groove;

(a) being disposed slightly inward of the pheriphal edge of the chip,

(b) extending through the silicon layer and through the oxide layer and partially into the substrate to prohibit impurities in the oxide layer outside the isolation barrier from diffusing into the oxide layer inside the isolation barrier, and

(c) surrounding completely the active area of the chip; and

a passivation layer on the silicon layer and extending to and partially over the groove.