US EPA

3562624 

Journal Article 

REACTIVE ION ETCHING OF THIN GOLD-FILMS 

Ranade, RM; Ang, SS; Brown, WD 

1993 

1 

Journal of Electrochemical Society
ISSN: 0013-4651
EISSN: 1945-7111 

140 

12 

3676-3678 

10.1149/1.2221148 

WOS:A1993MQ35000063 

Reactive ion etching of thin gold films using chlorine
(Cl-2), carbon tetrafluoride (CF4), carbon tetrachloride (CCl4), and a mixture of these gases was
investigated. Etch rates were studied by changing the etching gas composition, pressure, and
power in a parallel-plate reactive ion etcher. Reactive ion etching of gold using Cl-2 or CCl4
yields a low etch rate and a carbon residue formation on etched surfaces. The introduction of CF4
to the Cl-2 did not improve the etch rate. However, the addition of CF4 to CCl4 was found to etch
the carbon residue and significantly enhance the etch rate of gold. The etch rate of gold varies
from 30 Angstrom/min using a chlorine plasma to 990 Angstrom/min using a mixture of CF4 and CCl4.
For a mixture of CF4 and CCl4, the etch rate of gold was found to be twice the etch rate of
positive photoresist, suggesting that positive photoresist is a practical mask for most
applications involving the reactive ion etching of thin gold films.