JPS6356310B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vacuum deposition apparatus. The vapor deposition apparatus of the present invention uses an improved planetary rotating jig to achieve uniform vapor deposition on the vapor deposition substrate. Conventionally, in a vapor deposition apparatus, especially a vacuum vapor deposition apparatus, the vapor deposition substrate is directly held on a flat plate or circular dome-shaped umbrella provided above the vapor deposition source, and this umbrella is rotated and rotated like a planetary rotation. The aim was to achieve uniform vapor deposition on the substrate. This is shown in Figure 1. 1st
In the vapor deposition apparatus shown in FIG. Do some exercise. On the other hand, Fig. 1 b is a cross-sectional view of a part of this umbrella, and its plan c is
As shown in FIG. 2, a substrate 4 such as a silicon wafer or a lens used for a semiconductor integrated circuit is fixed to this umbrella by a holding spring 3, and it makes a planetary motion according to the umbrella 2 with respect to the evaporation source 1.

As a result, the evaporation flow from the evaporation source 1 is incident over the entirety of each substrate, and a uniform thin film is formed on the substrate 4.

However, especially for forming thin films on integrated circuits such as recent miniaturized LSIs, sufficient uniformity is required on uneven surfaces, and conventional vapor deposition equipment such as the one described above does not provide sufficient uniformity. It was hot.

The present invention has been made in view of these drawbacks, and it is an object of the present invention to provide a vapor deposition apparatus capable of highly uniform vapor deposition with a simple jig configuration.

Recently, in order to improve the uniformity of the deposited film on the substrate, a mechanism has been developed in which not only the umbrella revolves and rotates, but also a rotation axis is installed at the root of the holder that holds the substrate, and the holder is also rotated independently using a belt etc. A vapor deposition apparatus has been proposed.

However, such a device has a very complicated mechanism, and it is particularly difficult to maintain lubrication in the vacuum of the rotating system, making it difficult to put it into practical use.

The present invention achieves the above object by making use of the gravity applied to the substrate itself to spontaneously cause the substrate itself to rotate in accordance with the planetary rotation of the umbrella.

Embodiments of the present invention will be described below with reference to the drawings.
As shown in FIG. 1, the overall configuration of the vapor deposition apparatus of the first embodiment is such that a flat or circular dome-shaped vapor deposition umbrella 2 is placed above an evaporation source 1 with its axis of rotation tilted. This umbrella 2 has a revolution axis A and an autorotation axis B
It rotates planetarily relative to the In normal vapor deposition, the inclination of the rotation axis B with respect to the revolution axis A is preferably about 30° to 60° in consideration of the vapor deposition distribution.

On the other hand, inside the vapor deposition umbrella 2, as can be seen from the cross-sectional view of the umbrella shown in FIG. 2a and the plan view of FIG. 2b,
A plurality of substrate holders each including an outer ring portion 6 having an inner diameter R and a holding portion 7 are provided. Further, a substrate 4 such as a semiconductor wafer is held by an inner ring portion 5 having an outer diameter γ, and this substrate portion is held by the substrate holder in a freely movable state within the outer ring. The inner diameter R of the outer ring portion of the substrate holder is relative to the outer diameter γ of the inner ring portion 5 in the substrate portion.
is set large, so that the substrate portion is held in contact with one point on the circumference of the outer ring portion and the upper surface of the holding portion 7 with respect to the inclined substrate holder on the umbrella 2. That is, in Figure 1, the rotation axis B is relative to the revolution axis A.
When the substrate holder is arranged with an inclination of approximately 30° to 60°, the inner ring portion 5 contacts the outer ring portion 6 at a lower point on the circumference due to the difference in diameter of both rings and the action of gravity. To position. Therefore, if the umbrella performs planetary rotation such as revolution and rotation, the substrate part will spontaneously rotate within the outer ring on the umbrella. At this time, while the umbrella rotates once with respect to the rotation axis B, the contact point between the outer ring part 6 and the inner ring part 5 also rotates once. The outer diameter γ of the inner ring portion 5 is the same as that of the outer ring 6.
Since it is smaller than the inner diameter R, it will rotate by θ=R-γ/γ×360 (°) (R>γ).

By repeating this process, the inner ring part 5
The substrate 4 itself, which is fixed to the substrate 4, can also rotate on its own axis and perform planetary rotation relative to the evaporation source.

Generally, a metal film such as aluminum is placed on the wafer.
In order to form a layer of about 1 μm, vapor deposition is continued for about 5 minutes using an umbrella rotating at 20 revolutions per minute. At this time, it is desirable for the wafer itself to rotate at least 2 revolutions in order to achieve even and uniform vapor deposition on the wafer surface. .

Therefore, from the above formula, for uniform vapor deposition, the ratio R/γ of the inner diameter R of the substrate holder and the substrate portion γ is 1.02.
It turns out that the above is desirable.

As a result of the planetary rotation, it becomes possible to make the evaporation flow incident on the substrate 4 from all directions, and evaporation having a uniform thickness is performed regardless of the shape of irregularities on the substrate surface. Specific examples of its effectiveness include covering steps on silicon wafers used in semiconductor integrated circuits, and eliminating uneven film thickness when the substrate has a curvature like a lens.

Furthermore, by having a double ring holding structure including an outer ring and an inner ring as in this embodiment, it is possible to perform a good vapor deposition operation without damaging the periphery of the wafer.
Note that since the respective contact surfaces between the substrate part and the substrate holder, that is, the contact surfaces of the inner ring part 5, the outer ring part 6, and the holding part 7, are smooth, the umbrella 2
During rotation, the substrate can rotate smoothly on its own axis without flapping, and therefore a uniform film can be formed on the substrate.

FIG. 3 shows an embodiment using a lens 9 as the substrate.

In the above embodiments, the substrate part is a combination of the substrate and the inner ring part, but especially when the substrate is a flat plate like a wafer, the substrate part can be composed of the substrate itself as shown in Fig. 4. This also has the effects of the present invention. In this case, the substrate is formed into a circular shape having an outer diameter γ smaller than the inner diameter R of the substrate holder.

As described above, according to the method of the present invention, it is possible to perform vacuum deposition with a simple configuration and excellent uniformity on a substrate, which was impossible with conventional methods.

In addition, it has been difficult to obtain a symmetrical coating in the step coating of silicon wafers, but according to the present invention, it is possible to make the evaporation flow incident on the substrate from all directions, resulting in a symmetrical and uniform coating. A coating with a film thickness can be applied.

[Brief explanation of the drawing]

FIG. 1a is a cross-sectional side view showing an example of a vacuum evaporation apparatus having a planetary rotation mechanism using a conventional planetary jig. Figures 1b and 1c are views showing an example of a substrate (Si wafer) holding fixture that holds the substrate (Si wafer) on a substrate holder using the force of a spring, and Figure 2 is a first embodiment of the present invention. Figures 3 and 4 are diagrams showing the second and third embodiments, respectively. In the figure, A...revolution axis, B...rotation axis, 15...halogen lamp, 16...shutter, 17...key-shaped hole,
1... Evaporation source, 2... Evaporation umbrella, 3... Substrate holding metal fittings,
4...Substrate, 9...Lens, 5...Inner ring part, 6...
Outer ring part.

Claims (1)

[Claims] 1. An evaporation umbrella provided above an evaporation source and provided with a substrate holder for holding a substrate part is rotated around a revolution axis and an autorotation axis obliquely disposed with respect to the revolution axis. In a vapor deposition apparatus that performs vapor deposition on the substrate portion by planetary rotation, the substrate holder includes a ring portion having an inner diameter larger than an outer diameter of the substrate portion, and a holder that holds the substrate portion movably within the ring portion. 1. A vapor deposition apparatus comprising: a vapor deposition apparatus, wherein the substrate part itself rotates in conjunction with planetary rotation of the vapor deposition umbrella. 2. The vapor deposition apparatus according to claim 1, wherein the inner diameter of the ring portion is 2% or more larger than the outer diameter of the substrate portion.