Abstract An r. f. sputter coating apparatus includes an electrically isolated sputter shield surrounding the glow discharge region between anode and cathode. An r. f. signal may be applied to the shield to drive the glow discharge more positive with respect to anode potential. In addition, when sputtering conductive materials, a d. c. potential may be applied to the shield. When applying r. f. to the shield a variable inductance may be placed in parallel with the shield so as to form a parallel resonant circuit and maintain potential between shield and ground a maximum. A matching network is provided to assure maximum power transfer from the r.f. generator into the discharge. The network may include a vacuum capacitor formed within the dark space of the cathode on the cathode back side. Automatic electronic tuning of the matching network can be provided. A reactance tube variable network connected between the r. f. output and the matching network compensates for load circuit changes during sputtering. The shield may also be used to advantage in sputter etching equipment.
Inventors
👤 K Scow
👤 J Tuttle
Bibliographic Details
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-11-05 16:47
CPC Classifications
C; C23; C23C; C23C14/00; C23C14/22; C23C14/34
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
20 words
The invention defined by claim 1 wherein said shield is electrically isolated from said anode electrode, cathode electrode and chamber.
Claim 2
Dependent Claim
17 words
The invention defined by claim 1 wherein said shield is a metal cylinder surrounding said anode-cathode region.
Claim 3
Dependent Claim
11 words
The invention defined by claim 4 wherein said shield is apertured.
Claim 4
Dependent Claim
17 words
The invention defined by claim 1 including means for applying an r. f. signal to said shield.
Claim 5
Dependent Claim
15 words
The invention defined by claim 5 including a variable inductance in parallel with the shield.
Claim 6
Dependent Claim
100 words
An r.f. sputter apparatus comprising: a chamber adapted to be evacuated and maintain a low pressure of ionizable gas therein; an r.f. cathode electrode disposed within said chamber and adapted to support a glow discharge upon application of an r. f. signal to said cathode electrode and ensuing ionization of said ionizable gas; a radio frequency generator for producing a glow discharge in said ionizable gas, electrically connected to said cathode electrode; and, means closely spaced to said glow discharge for driving the potential of said discharge positive, said glow discharge driving means comprising a shield surrounding said glow discharge.
Claim 7
Dependent Claim
21 words
The invention defined by claim 7 wherein said glow discharge driving means is electrically isolated from said cathode electrode and chamber.
Claim 8
Dependent Claim
14 words
The invention defined by claim 7 including an electrical source connected to said shield.
Claim 9
Dependent Claim
16 words
The invention defined by claim 9 wherein said electrical source means is an r. f. generator.
Claim 10
Dependent Claim
15 words
The invention defined by claim 10 including a variable inductance in parallel with said shield.
Claim 11
Dependent Claim
55 words
In an r. f. sputtering apparatus, an r. f. cathode and an r. f. anode spaced from said cathode; means for creating a glow discharge between said cathode and said anode; and, means surrounding said glow discharge for driving said discharge positive with respect to said anode, said glow discharge driving means comprising a shield.