Device for applying thin layers onto a substrate

One piece hollow members 6, 7 supported at the wall of the vacuum chamber 1 are provided parallel to the plane of the cathode 12 and in the area between the cathode 12 and the anode 4, 5. These members have axis-parallel conduits 6a, 6b, 6d, 7a, 7b, 7d passed through by both the temperature-regulating medium and the process gas. The hollow members 6, 7 have openings 6e, 6e', . . . , 7e, 7e', . . . which run transversely to the longitudinal axis of the conduits for the process gas to emerge into the vacuum chamber 1.

BACKGROUND OF THE INVENTION 
The invention relates to a device for applying thin layers onto a substrate 
by means of cathode sputtering in a vacuum chamber. The substrate to be 
coated can be moved across this chamber in which a diaphragm is disposed 
between the cathode to be sputtered and the anode. Hollow members having 
conduits are provided parallel to the cathode plane and in the area 
between the cathode and the anode and held by the wall of the vacuum 
chamber. They are passed through by a temperature-regulating medium and by 
a process gas. The conduits are provided with openings for the process gas 
which run transversely to the longitudinal axis of this conduit and permit 
the process to emerge into the vacuum chamber. 
A device is known for applying thin layers onto a substrate by means of 
cathode sputtering (EP 0 205 028, to which U.S. Pat. No. 4,946,576 
correspond). Here, a mechanical diaphragm is provided between the cathode 
to sputtered and the anode separating the space between the cathode and 
the substrate to be sputtered. This device has several separate cooling 
pipes and gas pipes for the supply of temperature-regulating medium and 
process gas. 
It is a disadvantage of this known device that separate, multi-piece pipe 
lines must be used for the feeding and return of temperature-regulating 
medium as well as for the supply of process gas. The device is thus 
susceptible to failures and its manufacture and maintenance involves a 
great amount of labor and cost. The pipe lines exhibit bends, windings, 
screwed connections and soldering joints which, under operating conditions 
of the device, are inside a vacuum. This leads to hair cracks and leaks in 
the pipe lines caused by the additional effect of process heat. These 
leaks negatively affect the layer quality, for example, the adhesiveness 
of the layer to be applied onto the substrate during the sputtering and 
the consequence is a subsequent total failure of the entire system which 
always involves a significant amount of labor and immense costs. 
SUMMARY OF THE INVENTION 
It is therefore an object of the invention to improve the device in such a 
way that the operational safety is considerably improved and the failure 
times reduced and manufacture and maintenance are significantly 
simplified, which in turn leads to a substantial reduction of the 
manufacturing and maintenance costs. 
This object is accomplished in that both the temperature-regulating medium 
as well as the process gas are guided in conduits. These conduits are 
formed from a one-piece component which is formed as a hollow member and 
has openings for the gas to emerge which run transversely to the 
longitudinal axis of the conduits. 
The device has a hollow member which is characterized by a rectangular area 
of cross section with bevelled corners. 
The device has a hollow member having a rectangular cross section with 
bevelled corners. Advantageously, this member is simple to manufacture, 
has distinct and easily accessible contact points, and permits connecting 
temperature-regulating medium and process gas outside the vacuum chamber.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
As shown in FIG. 1, additional vacuum chambers 1', 1" are added to the side 
of the rectangular vacuum chamber 1. These additional chambers are 
connected to each other in one line by means of locks 2, 3. 
In a vacuum chamber 1, the anodes 4, 5 are disposed parallel to one another 
and transversely to the direction of extension of the chambers 1, 1', 1". 
The disposal is such that the rectangular hollow members 6, 7 and the 
diaphragms 8, 9 follow toward the center of the chamber. Conduits 6a, 7a 
for the feeding of the temperature-regulating medium (coolant) and 
conduits 6b, 7b for the return thereof are located above conduits 6d, 7d 
for the process gas in the centers of which the gas distributing pipes 6f, 
7f are mounted. Moreover, on their bottom sides, the conduits for the 
process gas 6d, 7d, . . . are provided with regularly spaced-apart 
openings 6e, 6e', . . . , 7e, 7e', . . . for the process gas to emerge 
from conduits 6d, 7d into the vacuum chamber 1. Underneath the anodes 4, 
the substrate 10 can be moved across the vacuum chamber in direction A on 
a horizontally extending substrate plane 11. 
Cathode 12 is above and between the diaphragms 8, 9 and extends parallel to 
the hollow members 6, 7 and hence transversely to the direction of moving 
A of the substrate. 
The two U-like sealing/baffle plates 13, 14 are disposed such that they 
close the gap which remains between the hollow members 6, 7 and the 
chamber walls of the vacuum chamber 1. 
By means of screw 16, the insulating bush 15 fixes the insulating ledge 17 
to which the anode 4 is attached via clamping device 4a in its position to 
the hollow member 6. Screw 18 connects the hollow member 7 to the 
diaphragm 9 via arresting bush 19 and clamping screw 20. 
At the front side, the flange for the process gas 21 and the screwed 
connection for the temperature-regulating medium 22 are mounted to the one 
end of the hollow member 6 which protrudes from the vacuum chamber 1. The 
flange for the process gas 21 is welded to the reducer piece 6g and 
together with the sealing ring 6i, it seals the conduit for the process 
gas 6d. Together with the sealing ring 61, the screwed connection for the 
temperature-regulating medium 22 seals the conduit for the 
temperature-regulating medium 6a, 6b (FIG. 2). 
The intermediate flange 23, the end flange 24, the threaded bolts 25, 25', 
. . . , the disks 26, 26', . . . and the nuts 27, 27', . . . fix the 
hollow member in its position in the vacuum chamber 1. The vacuum sealing 
rings 28, 29 seal this hollow member with respect to atmospheric pressure 
(FIG. 2). 
The connecting conduit 6c connects conduit 6a for the supply of 
temperature-regulating medium to the return conduit 6b (FIG. 3). 
The threaded bolts 25, 25', . . . , the disks 26, 26', . . . , and the nuts 
27, 27', . . . , which are symmetrically arranged on a partial circle 
arrest the end flange 24 in its position thus centering the rectangular 
hollow member 6 in its position at the wall of the vacuum chamber shown in 
FIG. 2 (FIG. 4). 
Referring to FIG. 5, the gas distributing pipe 6f has an opening 6k in the 
center of its axial extension for evenly distributing the process gas in 
the conduit 6d. This gas distributing pipe is disposed such that it is 
centered and axially fixed in its position by means of the reducer pieces 
6g, 6h. Together with the sealing ring 6i, it seals the gas conduit toward 
the hollow member 6. The flange 21 for the process gas is welded to the 
reducer piece 6g. On its bottom side, the conduit for the process gas 6d 
is provided with regularly spaced-apart openings 6e, 6e', . . . for the 
process gas to emerge from conduit 6d into the vacuum chamber already 
shown in FIG. 1.