Etching solution for silicon oxide and method of manufacturing a semiconductor device using the same

• US 20070090325A1
• Filed: 10/16/2006
• Published: 04/26/2007
• Est. Priority Date: 10/26/2005
• Status: Active Grant

• Current Assignee: Conversant Intellectual Property Management Inc (MOSAID Technologies Inc. (f/k/a Conversant Intellectual Property Management))
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Hwang, Dong-Won, Yi, Hun-Jung, Park, Jung-Dae, Lim, Kwang-Shin
• Granted Patent: US 7,351,667 B2
• Time in Patent Office: Days
• US Class Current: 252/79.1
• CPC Class Codes: H01L 21/31111 by chemical means
• CPC Class Codes: H01L 21/76816 Aspects relating to the layout of the pattern or to the size of vias or trenches layout of the interconnections per se H01L23/528; CAD of ICs G06F30/00
• CPC Class Codes: H10B 12/0335 Making a connection between the transistor and the capacitor, e.g. plug

Abstract

An etching solution for silicon oxide may be used in a process for enlarging an opening formed through a silicon oxide layer. The etching solution includes about 0.2 to about 5.0 percent by weight of a hydrogen fluoride solution, about 0.05 to about 20.0 percent by weight of an ammonium fluoride solution, about 40.0 to about 70.0 percent by weight of an alkyl hydroxide solution and remaining water. The etching solution may etch the silicon oxide layer without damage to a metal silicide layer exposed by the opening.

Claims

1. An etching solution for silicon oxide comprising:

about 0.2 to about 5.0 percent by weight of a hydrogen fluoride (HF) solution;

about 0.05 to about 20.0 percent by weight an ammonium fluoride (NH₄F) solution; and

about 40.0 to about 70.0 percent by weight of an alkyl hydroxide solution;

wherein the etching solution etches a silicon oxide layer preventing damage to a metal silicide layer exposed by an opening in a process for enlarging the opening through the silicon oxide layer.

2. The etching solution of claim 1, wherein the etching solution for silicon oxide is composed essentially of a hydrogen fluoride solution, an ammonium fluoride solution, an alkyl hydroxide solution and water.

3. The etching solution of claim 1, wherein the etching solution for silicon oxide includes weights of a hydrogen fluoride solution, an ammonium fluoride solution and an alkyl hydroxide solution with the remaining weight of the etching solution composed essentially of water.

4. The etching solution of claim 3, wherein the etching solution for silicon oxide comprises about 0.5 to about 2.0 percent by weight of the hydrogen fluoride solution, about 10.0 to about 18.0 percent by weight of the ammonium fluoride solution, about 50.0 to about 70.0 percent by weight of the alkyl hydroxide solution and remaining water when the silicon oxide layer includes HDP oxide.

5. The etching solution of claim 4, wherein an etch rate of the silicon oxide layer relative to the etching solution for silicon oxide is in a range of about 270 to about 350 Å

/minute.

6. The etching solution of claim 4, wherein a volume ratio of the hydrogen fluoride solution to the ammonium fluoride solution is in a range of about 1.0:

7.0 to 20.0.

7. The etching solution of claim 3, wherein the etching solution for silicon oxide comprises about 0.2 to about 0.5 percent by weight of the hydrogen fluoride solution, about 0.05 to about 0.2 percent by weight of the ammonium fluoride solution, about 55.0 to about 70.0 percent by weight of the alkyl hydroxide solution and water when the silicon oxide layer includes BPSG.

8. The etching solution of claim 7, wherein a volume ratio of the hydrogen fluoride solution to the ammonium fluoride solution is in a range of about 1.0:

0.2 to 0.5.

9. The etching solution of claim 3, wherein the alkyl hydroxide solution comprises an alcohol-based material.

10. The etching solution of claim 7, wherein the alkyl hydroxide solution comprises at least one selected from the group consisting of ethylene glycol, propylene glycol, glycerol, methanol, ethanol and isopropyl alcohol.

11. A method of manufacturing a semiconductor device, comprising:

forming a first contact pad and a second contact pad on a substrate;

forming a conductive structure including a metal silicide layer pattern electrically connected to the second contact pad;

forming a silicon oxide layer on the substrate to cover the conductive structure, the silicon oxide layer including a first opening exposing the first contact pad; and

etching the silicon oxide layer using an etching solution for silicon oxide while preventing damage to the metal silicide layer pattern to form a second opening having a width greater than that of the first opening,

wherein the etching solution comprises about 0.2 to about 5.0 percent by weight of a hydrogen fluoride solution, about 0.05 to about 20.0 percent by weight of an ammonium fluoride solution, about 40.0 to about 70.0 percent by weight of an alkyl hydroxide solution and water.

12. The method of claim 11, wherein the etching solution includes weights of a hydrogen fluoride solution, an ammonium fluoride solution and an alkyl hydroxide solution with the remaining weight of the etching solution composed essentially of water.

13. The method of claim 12, wherein the silicon oxide layer comprises at least one selected from the group consisting of BPSG, HDP oxide, PSG, USG, SOG, FOX and PE-TEOS.

14. The method of claim 12, wherein the etching solution for silicon oxide comprises about 0.2 to about 0.5 percent by weight of the hydrogen fluoride solution, about 0.05 to about 0.2 percent by weight of the ammonium fluoride solution, about 55.0 to about 70.0 percent by weight of the alkyl hydroxide solution, and remaining water when the silicon oxide layer includes BPSG.

15. The method of claim 12, wherein the etching solution for silicon oxide comprises about 0.5 to about 2.0 percent by weight of the hydrogen fluoride solution, about 10.0 to about 18.0 percent by weight of the ammonium fluoride solution, about 50.0 to about 70.0 percent by weight of the alkyl hydroxide solution, and remaining water when the silicon oxide layer includes HDP oxide.

16. The method of claim 11, wherein the alkyl hydroxide solution comprises an alcohol-based material.

17. The method of claim 16, wherein the alkyl hydroxide solution comprises at least one selected from the group consisting of ethylene glycol, propylene glycol, glycerol, methanol, ethanol and isopropyl alcohol.

18. The method of claim 11, prior to forming the silicon oxide layer, further comprising:

forming a first impurity region and a second impurity region on the substrate;

forming a first lower silicon oxide layer on the substrate to cover the first and the second impurity regions, wherein the first and the second contact pads are formed on the first and the second impurity regions through the first lower silicon oxide layer; and

forming a second lower silicon oxide layer on the first lower silicon oxide layer, wherein the conductive structure having a metal layer pattern on the metal silicide layer pattern is formed through the second lower silicon oxide layer.

19. The method of claim 11, wherein the second opening is formed to expose the metal silicide layer pattern of the conductive structure.

20. The method of claim 11, wherein the metal silicide layer pattern comprises one selected from the group consisting of titanium silicide, tantalum silicide, nickel silicide and copper silicide.