JPS6317253Y2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Technical Field of the Invention The present invention relates to the structure of a gate valve for a vacuum processing apparatus equipped with a feeding mechanism for semiconductor substrates to be processed.

(b) Background of the technology Semiconductor integrated circuits are manufactured on single-crystal thin-layer substrates (hereinafter referred to as wafers), whether they are single-element semiconductors such as silicon (Si) or germanium (Ge) or compound semiconductors such as gallium arsenide (GaAs). Patterns of conductive layers, insulating layers, etc. are formed thereon by combining film forming techniques such as vacuum evaporation and sputtering with etching techniques such as dry etching.

Most of these manufacturing processes are performed under high vacuum, and there are two methods for mass producing semiconductor integrated circuits: batch processing and in-line processing.

That is, the former method has the advantage of being able to process a large number of wafers at the same time, but has the disadvantage that the equipment becomes large-sized and that it cannot easily respond to processing demands that vary in growth conditions such as film thickness.

On the other hand, the latter processes one wafer at a time, making it relatively easy to adapt to changes in growth conditions such as film thickness. Therefore, it is necessary to shorten the processing time as much as possible.

The present invention relates to the structure of a gate valve used when a wafer is transferred to a semiconductor processing apparatus for forming integrated circuits using an in-line method.

(c) Prior Art and Problems There are various types of vacuum processing equipment used in the manufacture of semiconductor integrated circuits, but here we will explain the case of processing a Si wafer using a sputtering equipment as an example.

FIG. 1 is a block diagram of a sputtering apparatus, in which a wafer setting chamber (sender) 2 and a wafer receiving chamber (receiver) 3 are sandwiched between a central sputtering chamber 1, and preliminary exhaust chambers (load lock chambers) 4 and 5 are located between them. be.

In this sputtering apparatus, a plurality of Si wafers are loaded into a cassette and set in a wafer setting chamber 2, and thereafter they are sequentially fed one by one by a belt, and after a desired material has been sputter-grown in the sputtering chamber 1, they are transferred to a wafer receiving chamber. 3 and stored in a cassette.

In order to produce a film with constant quality and thickness, it is important to keep the environmental conditions in the sputtering chamber 1 as constant as possible and avoid exposing it to the atmosphere, as well as to mix as much impurity as possible that can degrade the film quality, such as moisture, into the sputtering chamber. It is important not to let this happen.

Therefore, preliminary evacuation chambers 4 and 5 are provided, and wafers are loaded or unloaded after being evacuated to a high vacuum using a vacuum pump, thereby preventing changes in the environment of the sputtering chamber 1.

That is, the wafer setting chamber 2 and the wafer receiving chamber 3 are at atmospheric pressure, while the sputtering chamber 1 is supplied with argon (Ar) through a needle valve or mass flow meter 6.
The sputtering is performed while maintaining a constant pressure by supplying an inert gas such as and evacuation by a vacuum pump 7.

Therefore, when replacing the wafer, if the gate valve separating the wafer setting chamber 2 and sputtering chamber 1 is opened and the wafer is carried in, the environment of the sputtering chamber 1 changes drastically and the quality of the thin film to be grown is reproduced. It is not suitable for mass production because it takes a long time to return the environmental conditions to a state where sputtering is possible.

For this purpose, preliminary exhaust chambers 4 are installed before and after the sputtering chamber.
5, and is configured to reduce environmental changes when loading or unloading wafers.

Therefore, gate valves 9 are installed before and after the preliminary exhaust chambers 4 and 5.
is provided and is evacuated by a vacuum pump.

When the wafer is transported by the belt transport method, the width of the gate valve 9 regulates the size of the wafer to be transported. That is, the gate valve 9 requires a considerable thickness for the valve operating mechanism in order to withstand pressure changes and perform opening/closing operations, resulting in the problem that the wafer cannot be transported unless the wafer size is considerably large.

(d) Purpose of the invention While conventional gate valve width determined the size of wafers that could be transferred, the purpose of this invention is to provide a gate valve mechanism that can transfer wafers smaller than this width. .

(e) Structure of the invention The object of the invention can be achieved by using a gate valve provided with a rotating mechanism or a sliding holding mechanism for guiding a semiconductor wafer to a movable valve body of the gate valve.

(f) Embodiment of the invention Figures 2 and 3 are cross-sectional views of the gate valve according to the invention, and Figure 2 shows the gate valve when it is closed and the gate valve when the gate valve is closed.
The figure shows an embodiment in which the gate valve is opened and a wafer is carried in. Although the gate valve 9 located between the preliminary exhaust chamber 4 and the sputtering chamber 1 on the right side in FIG. 1 is shown, other cases may also be used. Not much has changed.

In FIG. 2, the preliminary evacuation chamber 4 on the right side is initially at atmospheric pressure, while the sputtering chamber 1 on the left side is maintained at a high degree of vacuum.

Here, the gate valve consists of a gate valve holding part 10 and a movable valve body 11, and the gate valve holding part 10 is fixed so that the wafer introduction part 12 is aligned with the wafer introduction part of the sputtering chamber 1.

Next, the movable valve body 11, which exists in the gate valve holding part 10 with a slight gap, seals the wafer introduction part 12 of the gate valve holding part 10 in an airtight manner with a ring 13.

This is due to the pressure difference between the sputtering chamber 1 and the preliminary exhaust chamber 4.

In order to transfer the wafer 14 to the sputtering chamber, the pre-evacuation chamber 4 is evacuated by a vacuum pump to eliminate the pressure difference with the sputtering chamber 1, and the adhesive force between the movable valve body 11 and the gate valve holding portion 10 is eliminated. In the conventional method, the movable valve body 11 is pulled up using the air cylinder 15 in the relaxed state, and the wafer 14 is transferred to the opened wafer introduction section 12 by moving the belt 16 in the direction of the arrow.

However, in this state, the wafer 14 is inserted into the sputtering chamber 1.
In order to be transported to the sputter chamber, the diameter of the wafer 14 must be sufficiently larger than the sum of the thicknesses of the gate valve holder 10 and the side wall 18 of the sputter chamber. A small-diameter wafer that does not satisfy this condition is transported to the sputter chamber through the joint between the belt 16 of the preliminary exhaust chamber and the belt 17 of the sputter chamber, i.e., the gate valve holder 10 or the side wall 18 of the sputter chamber.
This prevented the wafer 14 from being transported.

That is, conventionally, the transfer of the wafer 14 has been restricted depending on the thickness of the gate valve mechanism.

The present invention equips the conventional movable valve body 11 with a wafer holding mechanism, which may be a rotating mechanism such as an idler or a holding mechanism that simply maintains the wafer 14 horizontally during transport. .

FIGS. 2 and 3 show an embodiment with an idler 19. FIG.

Here, the wafer holding mechanism such as the idler 19 is provided at the bottom of the movable valve body 11, and when the movable valve body 11 is pulled up using the air cylinder 15 as shown in FIG. There is an idler 19 below the slit 20, the position of which is designed to be equal to the upper position of the belts 16, 17 of the pre-evacuation chamber and the sputtering chamber.

In this case, the wafer 14 is supported at an intermediate position between the belts 16 and 17 when being transported to the sputtering chamber 1, so that the wafer 14 can be transported smoothly.

The wafer holding mechanism may be a support with a curvature instead of the idler 19 mentioned in this embodiment, but from the viewpoint of reducing sliding resistance, the idler 19 is
A rotation mechanism such as is advantageous.

(g) Effects of the invention By implementing the invention, manufacturing of semiconductor integrated circuits by the conventional in-line method was limited to large-diameter wafers, but it has become possible to produce small-diameter wafers as well.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram of the sputtering device, Figures 2 and 3
The figures are cross-sectional views of the gate valve according to the present invention, with FIG. 2 showing the closed state and FIG. 3 showing the open state. In the figure, 9 is a gate valve, 10 is a gate valve holding part, 11 is a movable valve body, 12 is an introduction part, 14 is a wafer, 16 and 17 are belts, 19 is an idler, 2
0 is slit.

Claims (1)

[Scope of Claim for Utility Model Registration] In a vacuum processing apparatus for forming semiconductor integrated circuits on a semiconductor processing substrate by an in-line method, a gate valve holding part is provided on a side wall part of the apparatus and partitioning processing chambers having different degrees of vacuum. A gate valve is provided with a gate valve consisting of a movable valve body, and the movable valve body blocks a wafer introduction part in a side wall part and a gate valve holding part to achieve airtight sealing, the movable valve body A rotating mechanism or a sliding holding mechanism is provided at the bottom of the valve body with a slit in between, and when the movable valve body is pulled up, a belt of a processing chamber provided across the rotating mechanism or sliding holding mechanism and the gate valve is connected to the belt. 1. A gate valve for a semiconductor vacuum processing apparatus, characterized in that the gate valve is configured such that the gate valves are maintained at substantially the same height.