Chemistry: electrical and wave energy – Apparatus – Coating – forming or etching by sputtering
Reexamination Certificate
2000-04-13
2001-04-17
Huff, Mark F. (Department: 1756)
Chemistry: electrical and wave energy
Apparatus
Coating, forming or etching by sputtering
C204S298110, C204S298070, C204S298230, C204S298260, C204S298280, C204S298120, C204S298170, C204S298180
Reexamination Certificate
active
06217730
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to the technical field of sputtering devices, and particularly to a multiple cathode sputtering device.
2. Related Art
A sputtering device is widely used in the field of semiconductor devices and liquid crystal display devices to form metallic thin films and insulation films.
Reference numeral
102
in FIG.
10
(
a
) shows an example of a sputtering device.
This sputtering device
102
has a vacuum chamber
111
, with a substrate holder
113
arranged on the bottom of the vacuum chamber
111
, and a target holder
115
arranged close to the ceiling of the vacuum chamber
111
at a position above the substrate holder
113
. A plurality of cylindrical shield tubes
106
are provided on a substrate holder
113
side surface of the target holder
115
(in this drawing three shield tubes
106
1
-
106
3
are shown).
Targets
105
1
-
105
3
are arranged one each inside the shield tubes
106
1
-
106
3
, and when a substrate on which a film is to be formed is placed on the substrate holder
113
the substrate and each of the targets
115
face each other.
When sputtering is carried out with this sputtering device
102
, among particles ejected from the each of the targets
105
1
-
105
3
, those that are ejected diagonally become deposited to the shield tube
106
, and only particles that fly out vertically can pass through the shield tube
106
.
Reference numeral
112
in FIG.
10
(
b
) represents as substrate mounted on the substrate holder
113
, and if sputtering particles that have passed through the shield tube
106
are incident on the substrate
112
, an angle formed by those sputtering particles and the surface of the substrate
112
becomes a minimum of &phgr;(incident angle is &pgr;/2−&phgr;). When the particles are incident at this angle &phgr;, the incident angle of the sputtering particles becomes maximum.
A rotating shaft
117
is attached to a rear surface of the target holder
115
. The rotating shaft
117
is airtightly lead through to the outside of the vacuum chamber
111
. Rotation of the rotating shaft
117
causes rotation of the target holder
115
, and each of the targets
105
1
-
105
3
can be horizontally rotated parallel to the substrate holder
113
. Reference numeral
118
represents the rotational axis of the rotating shaft
117
.
With this type of sputtering device
102
, if sputtering is carried out while rotating the target holder
115
, a thin film is uniformly formed on the surface of the substrate
112
with a small incident angle of the sputtering particles to the surface of the substrate
112
. Accordingly, uniform film formation is also possible inside microscopic holes having a high aspect ratio.
However, since sputtering particles deposit to the inner walls of the shield tubes
106
1
-
106
3
, a thin film is also formed at this section, and a problem occurs in that this film breaks up into smallness dust. Also, even if surface treatment to prevent smallness dust being generated is performed on the inner wall surfaces of the shield tubes
106
1
-
106
3
, it is difficult to insert a spray gun inside the tube.
Also, when reactive sputtering is carried out, not only sputtering gas but also reactant gas infiltrates into the shield tubes
106
1
-
106
3
, which causes problems such as a metallic target surface being nitrided (for example, TiN being formed on a Ti target surface), a reduction in sputter yield, and lowering of film deposition rate.
SUMMARY OF THE INVENTION
The present invention has been conceived in view of the above described drawbacks, and an object of the present invention is to provide a sputtering device that enables a small incident angle without using a cylindrical shield.
In order to achieve the above described object, a first aspect of the present invention is a sputtering device comprising, a vacuum chamber, a substrate holder arranged inside the vacuum chamber for holding a substrate, a plurality of targets arranged with surfaces opposite a substrate on the substrate holder, and a plurality of shield plates provided with a plurality of holes and arranged parallel to each other between the substrate holder and each of the targets, with spaces maintained between the shield plates.
With the present invention, each of the targets can be made to face the substrate holder through holes in each of the shield plates.
In such a case, it is possible for a normal line perpendicular to the surface of each target to pass through the holes in each shield plate and reach the surface of the substrate arranged on the substrate holder. At least the normal line in the center of the target which is perpendicular to the surface of each target, or the normal line in the center of the cathode electrode which is perpendicular to the surface of each cathode electrode, passes through the holes in each shield plate. These normal lines reach the surface of the substrate arranged on the substrate holder perpendicularly.
It is possible to arrange each target above the substrate holder. In such a case, thin film deposited to each shield plate does not fall off.
Also, it is possible for the sputtering device of the present invention to be configured so that each of the targets and each of the shield plates are rotated relative to the substrate holder while being stationary with respect to each other.
In this case, it is possible to rotate the target and each shield plate with the substrate stationary with respect to the vacuum chamber. On the other hand, it is also possible to rotate the substrate with the target and each shield plate stationary with respect to the vacuum chamber.
It is possible to fix each target to the same target holder.
With the sputtering device of the present invention, it is also possible to provide a first gas inlet, for introducing sputtering gas, and a second gas inlet, for introducing reactant gas, in the vacuum chamber.
In this case, it is possible to arrange the first gas inlet closer to the target than the second gas inlet.
Also in this case, it is possible for sputtering gas introduced into the vacuum chamber from the first gas inlet to be introduced between the target and a shield plate closest to the target, and for reactant gas introduced from the second gas inlet to be introduced between the substrate holder and the shield plate closest to the substrate holder.
The sputtering device of the present invention can further comprise a stick preventive tube arranged between the substrate holder and the target, having one opening section facing the substrate holder side, and another opening section facing the target side, with each of the shield plates being arranged inside the stick preventive tube.
In this case, each shield plate can be removably attached to the stick preventive tube.
It is also possible to have a shield ring arranged at an outer portion of the stick preventive tube, with a space inside the vacuum chamber being partitioned into a target side and a substrate holder side by the shield ring and the shield plates.
Also, when the first and second gas inlets are provided, it is possible to provide the first gas inlet for introducing sputtering gas into the vacuum chamber on the target side of the vacuum chamber, and to provide the second gas inlet for introducing reactant gas into the vacuum chamber on a substrate holder side of the vacuum chamber.
With the above described structure, the present invention has a substrate holder located inside a vacuum chamber, and a plurality of targets arranged at a position opposite the substrate holder.
A plurality of shield plates are arranged between the substrate holder and the target. Each shield plate is arranged so as to be substantially parallel to a substrate arranged on the substrate holder. The shield plates are arranged with spaces between them.
Holes are respectively provided in each shield plate at positions opposite to each target (that is, on a normal line of the surface of each target), and each target is configured so as to face the substrate holder through the holes.
With such str
Higuchi Yasushi
Komatsu Takashi
Kondo Tomoyasu
Nakajima Kuniaki
Sahoda Tsuyoshi
Armstrong Westerman Hattori McLeland & Naughton LLP
Chacko-Davis Daborah
Huff Mark F.
Nihon Shinku Gijutsu Kabushiki Kaisha
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