Iodine-containing compounds for etching semiconductor structures

Patent metadata

Field	Value
Publication number	US-11430663-B2
Application number	US-202016807247-A
Country	US
Kind code	B2
Filing date	Mar 3, 2020
Priority date	Dec 30, 2016
Publication date	Aug 30, 2022
Grant date	Aug 30, 2022

Abstract

A method for etching silicon-containing films is disclosed. The method includes the steps of introducing a vapor of an iodine-containing etching compound into a reaction chamber containing a silicon-containing film on a substrate, wherein the iodine-containing etching compound has the formula CaHxFyIz, wherein a=1-3, x=0-6, y=1-7, z=1-2, x+y+z=4 when a=1, x+y+z=4 or 6 when a=2, and x+y+z=6 or 8 when a=3; introducing an inert gas into the reaction chamber; and activating a plasma to produce an activated iodine-containing etching compound capable of etching the silicon-containing film from the substrate.

First claim

What is claimed is:

1. A method of forming a patterned structure, the method comprising:
introducing a vapor of an iodine-containing etching compound into a reaction chamber containing a silicon-containing film on a substrate, wherein the iodine-containing etching compound is selected from the group consisting of C 2 H 2 FI, C 3 HF 6 I, C 3 H 3 F 2 I, C 3 H 4 FI, C 3 H 5 F 2 I, C 3 H 6 FI, C 2 HFI 2 , C 2 H 2 F 2 I 2 , C 2 H 3 FI 2 , C 2 F 2 I 2 , C 3 HF 3 I 2 , C 3 HF 5 I 2 , C 3 H 2 F 4 I 2 , C 3 H 3 F 3 I 2 , C 3 H 4 F 2 I 2 and C 3 H 5 FI 2 ;
introducing an inert gas into the reaction chamber; and
activating a plasma to produce an activated iodine-containing etching compound capable of etching the silicon-containing film from the substrate to form the patterned structure; and
removing volatile by-products from the reaction chamber, wherein the activated iodine-containing etching compound reacts with the silicon-containing film to form the volatile by-products.

2. The method of claim 1 , wherein the iodine-containing etching compound is C 3 HF 6 I.

3. The method of claim 1 , further comprising introducing an oxidizer into the reaction chamber.

4. The method of claim 3 , wherein the oxidizer is selected from the group consisting of O 2 , CO, CO 2 , NO, N 2 O, and NO 2 .

5. The method of claim 3 , wherein the method produces an aperture in the silicon-containing film having an aspect ratio between approximately 10:1 and approximately 200:1.

6. The method of claim 3 , wherein the method produces an aperture in the silicon-containing film having a diameter ranging from approximately 5 nm to approximately 100 nm.

7. The method of claim 1 , wherein the silicon-containing film comprises a layer of silicon oxide, silicon nitride, polysilicon, crystalline silicon, low-k SiCOH, SiOCN, SiON, Si a O b H c C d N e , where a>0; b, c, d and e≥0, or combinations thereof.

8. The method of claim 7 , wherein the silicon-containing film is selectively etched from an amorphous carbon layer or a photoresist layer.

9. The method of claim 7 , wherein the silicon oxide layer is selectively etched from a silicon nitride, polysilicon or amorphous carbon layer.

10. The method of claim 1 , wherein the inert gas is selected from the group consisting of He, Ar, Xe, Kr, and Ne.

11. The method of claim 1 , further comprising introducing an etch gas into the reaction chamber.

12. The method of claim 11 , wherein the etch gas is selected from the group consisting of cC 4 F 8 , cC 5 F 8 , C 4 F 6 , CF 4 , CH 3 F, CF 3 H, CH 2 F 2 , COS, F—C≡N, CS 2 , SO 2 , trans-1,1,1,4,4,4-hexafluoro-2-butene (trans-C 4 H 2 F 6 ), cis-1,1,1,4,4,4-hexafluoro-2-butene (cis-C 4 H 2 F 6 ), hexafluoroisobutene (C 4 H 2 F 6 ), trans-1,1,2,2,3,4-hexafluorocyclobutane (trans-C 4 H 2 F 6 ), 1,1,2,2,3-pentafluorocyclobutane (C 4 H 3 F 5 ), 1,1,2,2-tetrafluorocyclobutane (C 4 H 4 F 4 ), and cis-1,1,2,2,3,4-hexafluorocyclobutane (cis-C 4 H 2 F 6 ).

13. A method of minimizing damage to a patterned mask layer while forming a via or trench in a substrate, the method comprising:
introducing a vapor of an iodine-containing etching compound into a reaction chamber containing a substrate having a silicon-containing film disposed thereon and a patterned mask layer disposed on the silicon-containing layer, wherein the iodine-containing etching compound is selected from the group consisting of C 2 H 2 FI, C 3 HF 6 I, C 3 H 3 F 2 I, C 3 H 4 FI, C 3 H 5 F 2 I, C 3 H 6 FI, C 2 HFI 2 , C 2 H 2 F 2 I 2 , C 2 H 3 FI 2 , C 2 F 2 I 2 , C 3 HF 3 I 2 , C 3 HF 5 I 2 , C 3 H 2 F 4 I 2 , C 3 H 3 F 3 I 2 , C 3 H 4 F 2 I 2 and C 3 H 5 FI 2 ;
introducing an inert gas into the reaction chamber; and
etching the silicon-containing film from the substrate to form the via or trench by activating a plasma to form an activated iodine-containing etching compound.

14. The method of claim 13 , wherein the activated iodine-containing etching compound produces iodine ions that strengthen the patterned mask layer.

15. The method of claim 13 , wherein the iodine-containing etching compound is C 3 HF 6 I.

16. A method of reinforcing a patterned mask layer while forming a via or trench in a substrate, the method comprising:
introducing a vapor of an iodine-containing etching compound into a reaction chamber containing a substrate having a silicon-containing film disposed thereon and a patterned mask layer disposed on the silicon-containing layer, wherein the iodine-containing etching compound is selected from the group consisting of C 2 H 2 FI, C 3 HF 6 I, C 3 H 3 F 2 I, C 3 H 4 FI, C 3 H 5 F 2 I, C 3 H 6 FI, C 2 HFI 2 , C 2 H 2 F 2 I 2 , C 2 H 3 FI 2 , C 2 F 2 I 2 , C 3 HF 3 I 2 , C 3 HF 5 I 2 , C 3 H 2 F 4 I 2 , C 3 H 3 F 3 I 2 , C 3 H 4 F 2 I 2 and C 3 H 5 FI 2 ;
introducing an inert gas into the reaction chamber; and
implanting an I ion from the iodine-containing etching compound into the patterned mask while etching the silicon-containing film from the substrate to form the via or trench by activating a plasma to form an activated iodine-containing etching compound.

17. The method of claim 16 , wherein the activated iodine-containing etching compound produces iodine ions that strengthen the patterned mask layer.

18. The method of claim 16 , wherein the iodine-containing etching compound is C 3 HF 6 I.

Assignees

• Air Liquide American
• Air Liquide
• Air Liquide Electronics Us Lp

Inventors

• Surla Vijay
• Gupta Rahul
• Sun Hui
• Pallem Venkateswara R
• Stafford Nathan
• Marchegiani Fabrizio
• Omarjee Vincent M
• Royer James

Classifications

• H10P50/268

  of silicon-containing layers · CPC title

• H10P50/73

  using masks for insulating materials · CPC title

• H10P50/283 Primary

  by chemical means · CPC title

• H10P50/242

  of Group IV materials · CPC title

• H10P50/691

  for Group V materials or Group III-V materials · CPC title