ETCHING SOLUTION FOR AN ALUMINUM OXIDE FILM, AND METHOD FOR MANUFACTURING A THIN-FILM SEMICONDUCTOR DEVICE USING THE ETCHING SOLUTION

• US 20150099327A1
• Filed: 03/07/2014
• Published: 04/09/2015
• Est. Priority Date: 04/19/2013
• Status: Active Grant

• Current Assignee: JDI Design and Development GK
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Higashi, Hirofumi, Hidaka, Yoshiharu
• Granted Patent: US 9,290,695 B2
• Time in Patent Office: Days
• US Class Current: 438/104
• CPC Class Codes: C09K 13/04 containing an inorganic acid
• CPC Class Codes: C09K 13/06 with organic material
• CPC Class Codes: C23G 1/125 aluminium
• CPC Class Codes: H01L 21/31111 by chemical means
• CPC Class Codes: H01L 21/441 Deposition of conductive or insulating materials for electrodes
• CPC Class Codes: H01L 21/465 Chemical or electrical treatment, e.g. electrolytic etching to form insulating layers H01L21/469
• CPC Class Codes: H01L 29/66969 of devices having semiconductor bodies not comprising group 14 or group 13/15 materials comprising selenium or tellurium in uncombined form other than as impurities in semiconductor bodies of other materials, comprising cuprous oxide or cuprous iodide H01L21/02365
• CPC Class Codes: H01L 29/786 Thin film transistors, i.e. transistors with a channel being at least partly a thin film transistors having only the source or the drain region on an insulator layer H01L29/0653; thin film FinFETs H01L29/785
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate

Abstract

An etching solution includes: phosphoric acid having concentration of 30% by weight to 80% by weight; nitric acid having concentration of 10% by weight or less; and surfactant having concentration of 0.0005% by weight to 0.0050% by weight, wherein the etching solution is used for etching an aluminum oxide film having film density of 2.80 g/cm³ to 3.25 g/cm³.

Claims

1. An etching solution comprising:

phosphoric acid having concentration of 30% by weight to 80% by weight;

nitric acid having concentration of 10% by weight or less; and

surfactant having concentration of 0.0005% by weight to 0.0050% by weight, wherein

the etching solution is used for etching an aluminum oxide film having film density of 2.80 g/cm³ to 3.25 g/cm³.

2. The etching solution of claim 1, wherein

the phosphoric acid has concentration of 50% by weight to 70% by weight, and

the nitric acid has concentration of 2% by weight to 4% by weight.

3. A manufacturing method of a thin-film semiconductor device, the manufacturing method comprising:

forming an aluminum oxide film having film density of 2.80 g/cm³ to 3.25 g/cm³ above an oxide semiconductor layer;

providing a through-hole in the aluminum oxide film by etching the aluminum oxide film with use of an etching solution, the etching solution including phosphoric acid having concentration of 30% by weight to 80% by weight, nitric acid having concentration of 10% by weight or less, and surfactant having concentration of 0.0005% by weight to 0.0050% by weight; and

embedding, in the through-hole provided in the aluminum oxide film, an electrode to be electrically connected with the oxide semiconductor layer.

4. The manufacturing method of claim 3, wherein

the phosphoric acid has concentration of 50% by weight to 70% by weight, and

the nitric acid has concentration of 2% by weight to 4% by weight.

5. The manufacturing method of claim 3, further comprising, between forming the aluminum oxide film and providing the through-hole in the aluminum oxide film:

forming a protection film on the aluminum oxide film;

providing a through-hole in the protection film by etching the protection film with use of fluorine-based gas; and

performing plasma processing, with use of oxygen-based gas, on part of the aluminum oxide film that is exposed through the through-hole provided in the protection film.

6. The manufacturing method of claim 5, wherein

the protection film has a single-layer structure consisting of any one of a silicon nitride film, a silicon oxide film, and a silicon oxynitride film, or a multi-layer structure consisting of at least two of the silicon nitride film, the silicon oxide film, and the silicon oxynitride film.