Trap rich layer formation techniques for semiconductor devices
View Patent ↗A trap rich layer for an integrated circuit chip is formed by chemical etching and/or laser texturing of a surface of a semiconductor layer. In some embodiments, a trap rich layer is formed by a technique selected from the group of techniques consisting of laser texturing, chemical etch, irradiation, nanocavity formation, porous Si-etch, semi-insulating polysilicon, thermal stress relief and mechanical texturing. Additionally, combinations of two or more of these techniques may be used to form a trap rich layer.
1. A method comprising:
forming a trap rich layer for an integrated circuit by chemical etching or laser texturing of a surface of a semiconductor layer; and
forming a circuit layer for the integrated circuit;
wherein the trap rich layer remains in a final structure for the integrated circuit chip; and
wherein the trap rich layer is located between the semiconductor layer and the circuit layer.
2. The method of claim 1 , wherein:
the trap rich layer is formed by chemical etching; and
the forming of the trap rich layer further comprises damaging the surface of the semiconductor layer before the chemical etching.
3. The method of claim 2 , wherein:
the damaging of the surface further comprises laser texturing the surface of the semiconductor layer.
4. The method of claim 2 , wherein:
the damaging of the surface further comprises mechanical texturing the surface of the semiconductor layer.
5. The method of claim 1 , wherein:
the trap rich layer is formed by chemical etching; and
the chemical etching is non-uniform.
6. The method of claim 1 , further comprising:
layer transferring a first structure containing the trap rich layer with a second structure containing the circuit layer.
7. The method of claim 1 , wherein:
the forming of the trap rich layer further comprises projecting energetic particles towards the semiconductor layer.
8. The method of claim 1 , wherein:
the trap rich layer is formed by chemical etching; and
the chemical etching further comprises wet chemical etching of the surface of the semiconductor layer.
9. The method of claim 1 , wherein:
the trap rich layer is formed by chemical etching; and
the chemical etching further comprises dry chemical etching of the surface of the semiconductor layer.
10. The method of claim 1 , wherein:
the forming of the trap rich layer is performed on a structure to contain the circuit layer before the forming of the circuit layer.
11. The method of claim 1 , wherein:
the forming of the trap rich layer is performed on a structure containing the circuit layer after the forming of the circuit layer.
12. The method of claim 1 , wherein:
the trap rich layer remains in a final structure for the integrated circuit.
13. A method comprising:
forming a trap rich layer for an integrated circuit by laser texturing of a surface of a semiconductor layer; and
forming a circuit layer for the integrated circuit;
wherein the trap rich layer remains in a final structure for the integrated circuit chip; and
wherein the trap rich layer is located between the semiconductor layer and the circuit layer.
14. The method of claim 13 , wherein:
the forming of the trap rich layer further comprises the laser texturing combined with a chemical etching of the surface of the semiconductor layer.
15. The method of claim 13 , wherein:
the forming of the trap rich layer by laser texturing further comprises directing a laser at a non-perpendicular angle to the surface of the semiconductor layer and rotating the semiconductor layer.
16. A method comprising:
in a semiconductor wafer, forming a trap rich layer by a technique selected from the group of techniques consisting of laser texturing, chemical etch, irradiation, nanocavity formation, porous Si-etch, semi-insulating polysilicon, thermal stress relief and mechanical texturing;
wherein the trap rich layer remains in a final structure for the integrated circuit chip; and
wherein the trap rich layer is located between the semiconductor layer and the circuit layer.
17. The method of claim 16 , further comprising:
forming the trap rich layer by at least two of the techniques selected from the group of techniques.
18. The method of claim 16 , wherein:
the forming of the trap rich layer further comprises combining at least one technique selected from the first group of techniques with at least one additional technique selected from a second group of techniques consisting of depositing polysilicon on a surface of the semiconductor wafer, depositing amorphous silicon on the surface of the semiconductor wafer, recrystallizing polysilicon at the surface of the semiconductor wafer, and damaging the surface of the semiconductor wafer by ion implantation.
19. The method of claim 16 , wherein:
the forming of the trap rich layer is performed on a structure to contain a circuit layer before forming of the circuit layer.
20. The method of claim 16 , wherein:
the forming of the trap rich layer is performed on a structure containing a circuit layer after forming of the circuit layer.