Method of patterning a transparent conductor

• US 5,094,978 A
• Filed: 07/19/1990
• Issued: 03/10/1992
• Est. Priority Date: 07/31/1989
• Status: Expired due to Term

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Miyagaki, Shinji, Ri, Seigen
• Primary Examiner(s): Hearn, Brian E.
• Assistant Examiner(s): NGUYEN, TUAN H
• Application Number:
  US07/554,367
• Time in Patent Office: 600 Days
• Field of Search: 437/181, 437/228, 437/225, 204/192.35, 156/643, 156/646, 156/667, 156/650, 156/651, 156/652
• US Class Current: 438/609
• CPC Class Codes: H01L 31/1884 Manufacture of transparent electrodes, e.g. TCO, ITO
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy
• CPC Class Codes: Y10S 438/963 Removing process residues from vertical substrate surfaces

Abstract

A method of forming a pattern of a transparent conducting film such as an indium tin oxide film, formed on the surface of a substrate including Si and being heated. A two-step etching method is employed, in which the transparent conducting film is wet-etched by an aqueous solution of a halogenide and thereafter an interfacial reacted layer generated at the interface of the transparent conducting film and substrate including Si is etched by a plasma etching method using a halogen.

Claims

1. A method of forming a patterned transparent conducting film in a fabrication of a semiconductor device, comprising the steps of:

(a) forming a transparent conducting film on a substrate including silicon, said transparent conducting film including an interfacial reacted layer adjacent to said substrate;

(b) patterning a resist film after forming said resist film on said transparent conducting film;

(c) wet-etching said transparent conducting film so as to expose said interfacial reacted layer by using an etchant including a halogenide and by using the patterned resist film as a mask; and

(d) dry-etching the exposed interfacial reacted layer by using a reactive gas including a halogen.

2. A method of forming a patterned transparent conducting film according to claim 1, wherein said transparent conducting film includes at least any one of indium oxide (In₂ O₃), tin oxide (SnO₂), and zinc oxide (ZnO).

3. A method of forming a patterned transparent conducting film according to claim 1, wherein said substrate is formed by any one of silicon (Si), siliconcarbide (SiC), silicon-germanium (SiGe), spin on glass (SOG), phosphosilicate glass (PSG), silicon dioxide (SiO₂), boro-phosphosilicate glass (BPSG).

4. A method of forming a patterned transparent conducting film according to claim 1, wherein said etchant is any one of an aqueous solution of ferric chloride (FeCl₃), hydrochloric acid (HCl), hydroiodic acid (HI), hydrobromic acid (HBr), and a mixed acid of hydrochloric acid and nitric acid.

5. A method of forming a patterned transparent conducting film according to claim 4, wherein said etchant is a 30 to 40% aqueous solution of ferric chloride (FeCl₃) and wherein step (c) is carried out at the temperature of 30°

to 60°

C.

6. A method of forming a patterned transparent conducting film according to claim 1, wherein said reactive gas is any one of fluorine (F₂), nitrogen trifluoride (NF₃), tetrafluoromethane (CF₄), hexafluoroethane (C₂ F₆), octafluoropropane (C₃ H₈), hydrogen fluoride (HF), chlorine (Cl₂), tetrachloromethane (CCl₄), hydrogen chloride (HCl), diclorosilane (SiH₂ Cl₂), tetrachloro-difluoroethane (C₂ F₂ Cl₄), trifluoromethane (CHF₃), bromine (Br₂), hydrogen bromide (HBr).

7. A method of forming a patterned transparent conducting film according to claim 6, wherein said reactive gas is nitrogen triluroide (NF₃) and wherein step (d) is carried out by a plasma etching method under the conditions that pressure is 0.3 to 1.0 Torr and frequency power is 0.05 to 0.3 W/cm².

8. A method of forming a patterned transparent conducting film according to claim 1, wherein said etchant is a 30 to 40% aqueous solution of ferric chloride (FeCl₂) and wherein step (c) is carried out at the temperature of 30°

to 60°

C.

9. A method of forming a patterned transparent conducting film according to claim 1, wherein said reactive gas is nitrogen trifluoride (NF₃) and wherein step (d) is carried out by a plasma etching method under the conditions that pressure is 0.3 to 1.0 Torr and frequency power is 0.05 to 0.3 W/cm².

10. A method of forming a patterned transparent conducting film according to claim 1, wherein step (a) includes the substep of:

forming said transparent conducting film on a surface of said substrate while said substrate is being heated at a temperature of more than 100°

C.