Method of manufacturing a base substrate for a semi-conductor on insulator type substrate

• US 8,765,571 B2
• Filed: 03/21/2012
• Issued: 07/01/2014
• Est. Priority Date: 03/22/2011
• Status: Active Grant

• Current Assignee: Soitec S.A.
• Original Assignee: Soitec S.A.
• Inventors: Kononchuk, Oleg, Allibert, Frederic
• Primary Examiner(s): Mandala, Michelle
• Application Number:
  US13/426,190
• Publication Number:
  US 20120244687A1
• Time in Patent Office: 832 Days
• Field of Search: 438/403, 438/476, 438/906, 257/E23.016, 257/E21.32, 257/E21.561
• US Class Current: 438/403
• CPC Class Codes: H01L 21/02164 the material being a silicon oxide, e.g. SiO2
• CPC Class Codes: H01L 21/0223 formation by oxidation, e.g. oxidation of the substrate
• CPC Class Codes: H01L 21/02301 in-situ cleaning
• CPC Class Codes: H01L 21/76251 using bonding techniques
• CPC Class Codes: H01L 21/76262 using selective deposition of single crystal silicon, i.e. SEG techniques

Abstract

A method and system are provided for manufacturing a base substrate that is used in manufacturing a semi-conductor on insulator type substrate. The base substrate may be manufactured by providing a silicon substrate having an electrical resistivity above 500 Ohm·cm; cleaning the silicon substrate so as to remove native oxide and dopants from a surface thereof; forming, on the silicon substrate, a layer of dielectric material; and forming, on the layer of dielectric material, a layer of poly-crystalline silicon. These actions are implemented successively in an enclosure.

Claims

1. A method of manufacturing a high resistivity base substrate, which comprises:

(a) providing a silicon substrate having an electrical resistivity above 500 Ohm·

cm,

(b) cleaning the silicon substrate so as to remove native oxide and dopants from a surface thereof,

providing, on the silicon substrate, a layer of dielectric material,

(d) providing, on the layer of dielectric material, a layer of poly-crystalline silicon, and

implementing steps (b), (c) and (d) successively in the same enclosure to minimize loss of resistivity of the poly-crystalline layer of the substrate.

2. The method according to claim 1, wherein the cleaning comprises a heat treatment in a reducing atmosphere.

3. The method according to claim 1, wherein the dielectric material comprises silicon oxide.

4. The method according to claim 3, wherein the providing of the layer of dielectric material comprises conducting a heat treatment of the silicon substrate in an oxidizing atmosphere to form the layer.

5. The method according to claim 4, wherein the oxidizing atmosphere comprises an inert gas having between 100 and 5000 ppm oxygen.

6. The method according to claim 1, wherein the layer of poly-crystalline silicon is deposited at a temperature of less than or equal to 900°

C.

7. The method according to claim 1, wherein the enclosure comprises an epitaxy frame.

8. The method according to claim 1, wherein the enclosure comprises a first chamber for cleaning the silicon substrate, a second chamber for providing the layer of dielectric material and a third chamber for providing the layer of poly-crystalline silicon, the chambers being connected via airlocks isolated from an exterior.

9. A method for the manufacture of a semi-conductor on insulator type substrate method which comprises transferring onto the base substrate according to claim 1 a layer of insulating material and a useful layer of semiconductor material to form the semi-conductor on insulator type substrate.

12. The method according to claim 1, which further comprises providing the enclosure with a first chamber for cleaning the silicon substrate, a second chamber for forming the layer of dielectric material and a third chamber for forming the layer of poly-crystalline silicon, and connecting the chambers via airlocks to isolate the enclosure from the surrounding atmosphere.

13. The method according to claim 12, which further comprises one or more of:

accessing the enclosure for introducing or extracting substrates therefrom,

closing the enclosure to shut off the access means in a sealed manner,

supporting the substrate during cleaning or formation of layers thereon, or

heating the enclosure.

14. The method according to claim 12, which further comprises:

introducing gases or reagents of suitable composition for conducting the various steps for manufacturing the base substrate, and

extracting residual gases or reagents after each step is conducted.

15. A method for minimizing loss of resistivity of a poly-crystalline layer of a high resistivity base substrate, which comprises preparing the base substrate according to the method of claim 1.

10. A method for avoiding contamination when providing a high resistivity base substrate, which comprises providing an enclosure for preparation of the substrate therein, wherein the substrate is prepared by conducting successively the following steps in the enclosure:

(a) providing a silicon substrate having an electrical resistivity above 500 Ohm·

cm,

(b) cleaning the silicon substrate so as to remove native oxide and dopants from a surface thereof,

(c) providing, on the silicon substrate, a layer of dielectric material, and

(d) providing, on the layer of dielectric material, a layer of poly-crystalline silicon to form the base substrate;

wherein the substrate is prepared while minimizing loss of resistivity of the poly-crystalline layer of the substrate due to avoiding contamination.

11. The method according to claim 10, wherein the enclosure comprises a first chamber for cleaning the silicon substrate, a second chamber for providing the layer of dielectric material and a third chamber for providing the layer of poly-crystalline silicon, the chambers being connected via airlocks isolated from an exterior.

16. A method of manufacturing a high resistivity base substrate, which comprises:

(a) providing a silicon substrate having an electrical resistivity above 500 Ohm·

cm,

(b) cleaning the silicon substrate in a reducing atmosphere so as to remove native oxide and dopants from a surface thereof,

(c) providing, on the silicon substrate, a layer of dielectric material comprising silicon oxide, and

(d) providing, on the layer of dielectric material, a layer of poly-crystalline silicon by deposition at a temperature of less than or equal to 900°

C.,

(e) implementing steps (b), (c) and (d) successively in the same enclosure to minimize loss of resistivity of the poly-crystalline layer of the substrate,

wherein the enclosure comprises a first chamber for cleaning the silicon substrate, a second chamber for forming the layer of dielectric material and a third chamber for forming the layer of poly-crystalline silicon, and the chambers are connected via airlocks to isolate the enclosure from the surrounding atmosphere.

17. The method according to claim 16, which further comprises one or more of:

accessing the enclosure for introducing or extracting substrates therefrom,

closing the enclosure to shut off the access means in a sealed manner,

supporting the substrate during cleaning or formation of layers thereon, or

heating the enclosure.