content_image/921312.jpg content_image/921310.jpg content_image/921309.jpg
# c12) United States Patent 

# Kezuka et al. 

# (54) ETCHING SOLUTION, ETCHED ARTICLE AND METHOD FOR ETCHED ARTICLE 

(75) Inventors: Takehiko Kezuka, Settsu (JP); Makoto Suyama, Settsu (JP); Mitsushi Itano, Settsu (JP) 

(73) Assignee: Daikin Industries, Ltd., Osaka (JP) 

( *) Notice: Subject to any disclaimer, the term ofthis patent is extended or adjusted under 35 U.S.C. 154(b) by O days. 

(21) Appl. No.: 09/856,358 

(22) PCT Filed: Nov. 22, 1999 

(86) PCT No.: PCT I JP99/06502 § 371 (c)(l), (2), ( 4) Date: May 22, 2001 

(87) PCT Pub. No.: WO00/31785 PCT Pub. Date: Jun. 2, 2000 

## (30) Foreign Application Priority Data 

Nov. 24, 1998 (JP) ................................. 10-332782 

(51) Int. Cl. B44C 1122 (2006.01) 

(52) U.S. Cl. ....................... 216/103; 216/106; 216/108; 252/79.1; 252/79.2 

(58) Field of Classification Search ................. 438/745, 438/756; 252/79.1, 79.2, 79.3, 79.4; 257/636; 216/103 See application file for complete search history. 

## (56) References Cited 

3,518,135 A 6/1970 Cerniglia et al. 

## U.S. PATENT DOCUMENTS 

<img src='content_image/921312.jpg'>

# (10) Patent No.: US 7,404,910 Bl 

# Jul. 29, 2008 (45) Date of Patent: 

<img src='content_image/921310.jpg'>

## FOREIGN PATENT DOCUMENTS 

<img src='content_image/921309.jpg'>

* cited by examiner 

Primary Examiner-Binh X Tran 

Assistant Examiner-Maki Angadi 

(74)Attorney, Agent, or Firm-B. Aaron Schulman; Stites & Harbison PLLC 

## (57) ABSTRACT 

An etching solution which contains hydrogen fluoride (HF) and exhibits an etching rate ratio: etching rate for a boron› glass film (BSG) or boron-phosphorus-glass film (BPSG)/ etching rate for a thermally oxidized film (THOX) of 10 or more at 25° C. 

US007404910Bl 

## 8 Claims, No Drawings 

