Gold Etchants
for Microelectronics Circuits

Selective etchants for gold, compatible with negative and positive photoresists-used in thin film microelectronics to develop circuit elements.

  • Etching readily controlled with minimum undercutting — provides excellent definition.
  • Room-temperature operated.
  • Uniform etch rates
  • Economical
  • Gold Etchants TFA, GE-8148, GE-8110, and GE-8111 are available in glass or plastic packaging depending on shipment method
GOLD ETCHANT TFA / GE-8148

DESCRIPTION:

These thin film etchants are used to obtain selective etching of gold in the photo fabrication of microelectronic circuits. Used in conjunction with photoresist technology, these etchants form precise electrodes and resistor patterns in thin films prepared on alumina and other substrates.

High purity, low sodium and 0.2 micron filtration for semiconductor and microelectronics applications.

Gold Etchant TFA - Cyanide free for standard applications.
GE-8148 - Cyanide free, no attack of nickel films.

 

TFA

GE-8148

Operating Temperature

Room Temperature

Room Temperature

Ventilation

Hood recommended

Hood recommended

Agitation

Work agitation; Speed accelerates etch rate

Work agitation; Speed accelerates etch rate

Tank

Glass

Glass

Etch Rate @ 25 °C

28Å/sec.

50Å/sec.

Composition

Ready -to - use liquid

Contains KI-I2 complex

Ready -to - use liquid

Contains KI-I2 complex - Phosphate compound

pH @ 20 °C

  

8.15 ± 0.2

Density @ 20 °C

  

1.265 ± 0.01

Etch Capacity gm/gal

100

100

Resist Compatibility

Neg & Pos.

Neg. & Pos.

Rinse

Distilled, Dionized Water

  

Waste Disposal

(Reclaim Gold in spent etchant.)

Dispose in accordance with all federal, state and local regulations. Send waste to an approved waste disposal facility.




Max. Impurity (ppm, Gold Etch TFA)

Sodium ( Na)

40

Chlorine & Bromides (Cl)

100

Lead (Pb)

5

Iron (Fe)

3

Sulfur (as sulfates)

50

Phosphorous (as phosphates in TFA)

10


GOLD ETCHANT
GE-8110
GE-8111

GE-8110 and GE-8111 Gold Etchants are etching solutions designed specifically for etching thin films of gold in the fabrication of semiconductor devices and thin film microelectronics. The solutions are based on potassium iodide and iodine ( KI/I2) chemistry and do not contain cyanide. They are compatible with both positive and negative photoresist materials, giving controllable line definition. GE-8110 is buffered to approximately pH 8.0 while GE-8111 is acidic with a lower solids content and is a slower acting etching solution. Both etchants should be used at room temperature in a well-ventilated area.

Physical and Chemical Properties:

Appearance and odor: dark brown liquid with iodine vapor odor.

 

GE-8110

GE-8111

pH (20 °C)

7.9 ± 0.1

2.5 ± 0.1

Density ( 20 °C)

1.33 ± 0.01

1.15 ± 0.01

Etch Rate ( 30 °C)

20Å/sec

30Å/sec

REAGENT GRADE CHEMICAL

IMPURITY

SPEC. PPM (MAX)

MAX-IMPURITY PPM

  

Sodium ( Na)

40

Chlorine & Bromides ( Cl)

100

Lead (Pb)

5

Iron (Fe)

3

Sulfur (as sulfates)

50


Storage and Handling

Store at room temperature away from sunlight. Keep container sealed when not in use. Iodine vapor can irritate the eyes severely. Open in ventilated areas. In case of contact with eyes or skin, wash with plenty of water (or soapy water for skin), and consult a physician if irritation persists.


GOLD ETCHANT TFAC
FOR INTERMETALLIC SUBSTRATES

DESCRIPTION:

Gold Etchant TFAC is a selective etchant for the preparation of microelectronic circuits on gallium arsenide, gallium phosphide, and other intermetallic semiconductor compounds. Gold Etchant TFAC provides excellent definition with minimal undercutting. Uniform etch rates are obtained with this cyanide based etchant. Gold Etchant TFAC strips gold from copper, brass, bronze, nickel, and other non-ferrous metals (except silver). Gold Etch TFAC is compatible with aluminum.

PROPERTIES:

Operating Temperature Room Temperature
Ventilation Hood
Agitation Work agitation speed accelerates etch rate
Tank Polypropylene
Etch Rate
25 oC
60 oC
5-10 Angstroms/second
30 angstroms/second
Composition Cyanide-containing powder.
Dilute with water (8oz /gal) prior to use.
Etch Capacity @ 60 °C 90grams/gal
Rinse Water
Disposal See Below


APPLICATION:

Warm water to approximately 50 °C to aid dissolution. Add 8oz Gold Etchant TFAC powder per gallon deionized water. Etch the conductor pattern to remove gold; etch time depends on thickness. Spent etchant should be saved for gold reclamation.

Disposal: Segregate solution. Cyanide should be handled carefully and disposed of according to local and state regulations.