METHOD FOR CURING DEFECTS IN A SEMICONDUCTOR LAYER

• US 20130026663A1
• Filed: 07/27/2012
• Published: 01/31/2013
• Est. Priority Date: 07/28/2011
• Status: Active Grant

• Current Assignee: Soitec S.A.
• Original Assignee: Soitec S.A.
• Inventors: Radu, Ionut, Gourdel, Christophe, Vetizou, Christelle
• Granted Patent: US 8,993,461 B2
• Time in Patent Office: Days
• US Class Current: 257/798
• CPC Class Codes: H01L 21/26506 in group IV semiconductors
• CPC Class Codes: H01L 21/26513 of electrically active species
• CPC Class Codes: H01L 21/324 Thermal treatment for modifying the properties of semiconductor bodies, e.g. annealing, sintering H01L21/20 - H01L21/288 and H01L21/302 - H01L21/322 take precedence
• CPC Class Codes: H01L 21/76254 with separation/delamination along an ion implanted layer, e.g. Smart-cut, Unibond

Abstract

A method for curing defects associated with the implantation of atomic species into a semiconductor layer transferred onto a receiver substrate, wherein the semiconductor layer is thermally insulated from the receiver substrate by a low thermal conductivity layer having thermal conductivity that is lower than that of the transferred semiconductor layer. The method includes applying a selective electromagnetic irradiation to the semiconductor layer to heat that layer to a temperature lower than its temperature of fusion to cure defects without causing an increase in the temperature of the receiver substrate beyond 500° C.

Claims

1. A method for curing defects associated with the implantation of atomic species into a semiconductor layer transferred onto a receiver substrate, the semiconductor layer being thermally insulated from the receiver substrate by a low thermal conductivity layer having thermal conductivity that is lower than that of the transferred semiconductor layer, wherein the method comprises applying a selective electromagnetic irradiation to the semiconductor layer to heat that layer to a temperature lower than its temperature of fusion to cure defects Without causing an increase in the temperature of the receiver substrate beyond 500°

C.

2. The method according to claim 1, wherein the selective electromagnetic irradiation has a wavelength chosen such that only the transferred semiconductor layer absorbs the irradiation.

3. The method according to claim 2, wherein the selective electromagnetic irradiation is a pulsed-laser irradiation with a selected energy density and duration of pulses that provide the recited heating of the semiconductor layer.

4. The method according to claim 3, wherein the transferred semiconductor layer is made of silicon and has a wavelength of irradiation that is shorter than 360 nm.

5. The method according to claim 4, wherein the energy and the duration of the pulses are chosen so as to heat the transferred layer to a temperature in the range between 800 and 1300°

C.

6. The method according to claim 1, wherein the receiver substrate comprises at least one electronic device, one functionalized region or one metallized region thereon or therein.

7. The method according to claim 1, wherein the transferred layer is a layer of silicon comprising an electrically functional portion and the low thermal conductivity layer comprises an oxide or nitride.

8. The method according to claim 1, wherein the low thermal conductivity layer has a thickness in the range between 10 and 10000 nm.

9. A method for fabrication of a semiconductor structure comprising a receiver substrate and a semiconductor layer, which method comprises:

implanting atomic species into a donor substrate to create a fragilization region subjacent the semiconductor layer to be transferred,

providing, on one of a donor substrate or receiver substrate or on both substrates, a low thermal conductivity layer whose thermal conductivity is lower than thermal conductivity of the semiconductor layer,

bonding of the donor and receiver substrates with the low thermal conductivity layer or layers therebetween,

fracturing the donor substrate along the fragilization region to transfer the semiconductor layer onto the receiver substrate, and

curing defects in the transfer layer by applying a selective electromagnetic irradiation to the semiconductor layer to heat that layer to a temperature lower than its temperature of fusion to cure defects without causing an increase in the temperature of the receiver substrate beyond 500°

C.

10. The method according to claim 9, which further comprises conducting a polishing of the transferred semiconductor layer surface after fracturing and before the curing of the defects.

11. The method according to claim 9, wherein the bonding is molecular bonding.

12. The method according claim 9, which further comprises associating a bonding layer on one of the donor substrate, the receiver substrate or on both substrates to facilitate bonding, wherein the bonding layer(s) have a thermal conductivity is greater than or equal to thermal conductivity of the semiconductor layer.

13. The method according to claim 12, wherein the bonding layer comprises a layer of silicon or metal.

14. The method according to claim 9, wherein the low thermal conductivity layer is discontinuous.

15. The method according to claim 9, wherein the electromagnetic irradiation is a pulsed-laser irradiation with a selected energy density and duration of pulses that provide the recited heating of the semiconductor layer.

16. The method according to claim 15, wherein the energy and the duration of the pulses are chosen so as to heat the transferred layer to a temperature in the range between 800 and 1300°

C.

17. The method according to claim 9, wherein the selective electromagnetic irradiation has a wavelength chosen such that only the transferred semiconductor layer absorbs the irradiation.

18. The method according to claim 17, wherein the transferred semiconductor layer is made of silicon and has a wavelength of irradiation that is shorter than 360 nm.

19. The method according to claim 9, wherein the transferred layer is a layer of silicon comprising an electrically functional portion and the low thermal conductivity layer comprises an oxide or nitride.

20. A semiconductor structure comprising a substrate and a semiconductor layer, with the substrate comprising at least one electronic device, one functionalized region, or one metallized region thereon or therein which is thermally insulated from the semiconductor layer by a low thermal conductivity layer having a thermal conductivity lower than thermal conductivity of the semiconductor layer, wherein the semiconductor layer comprises a portion having a P-type donor concentration higher than 10¹⁷ cm⁻

3.