JPS6245109A - Thermal treatment equipment - Google Patents

Abstract

PURPOSE:To treat materials to be treated continuously by stopping the materials to be treated for a fixed time in a soaking region in a furnace body in which the materials to be treated are transported in succession. CONSTITUTION:A fork 9 in a furnace body 3 can be moved vertically, and can be stopped at predetermined upper-step position, intermediate-step position and lower-step position. A recessed section 9a is formed extending over the length of approximately three cartridges at the central section of the fork 9, and structure in which the cartridge 8 on said recessed section 9a can be shifted only when the fork 9 is positioned at the upper-step position on said recessed section 9a is shaped.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a technique that is effective when applied to a heat treatment apparatus used for impurity diffusion treatment and the like in the manufacture of semiconductor devices and the like.

[Background Art] A heat treatment apparatus is known that heats a wafer in a predetermined fluid atmosphere in order to activate impurities introduced into a semiconductor wafer (hereinafter simply referred to as a wafer) by ion implantation.

Such heat treatment equipment is, for example, an electric furnace structure with an entrance and exit at one end, in which a plurality of wafers are placed upright on a boat-shaped jig and transported into the furnace, and the boat is pulled back again after processing. It is widely known that the wafer is transported outside together with the jig.

However, in the heat treatment apparatus having the above structure, the jig is moved in and out of the electric furnace from only one direction, so the amount of heat received by the wafer differs depending on the position of the wafer in the jig, and therefore uniform processing cannot be expected. In addition, the inventors have revealed that the above structure does not have good processing efficiency because loading and unloading cannot be carried out at the same time.

Therefore, as described in JP-A-56-110228 or JP-A-58-220423, there is a transfer structure in which wafers are carried into the furnace from one direction and taken out from the other direction. A heat treatment device can be considered.

However, among the above, the former has a structure in which the wafer is placed upright in the thread groove of a feed screw extending into the furnace, and the wafer is continuously moved within the furnace by rotating the feed screw. However, the inventors have found that friction between the threaded portion and the wafer may cause damage to the wafer or dust generation.

In addition, the latter type has a structure in which the object to be processed is transported by the fluid pressure of an inert fluid such as nitrogen gas, but the transport time cannot be kept constant and the processing may become uneven. The inventor has also discovered that there is a possibility that foreign matter such as dust may be drawn into the furnace along with the fluid.

For this reason, it is conceivable to pass the wafer through the furnace at a uniform speed using a transfer means such as a conveyor mechanism, but with such a method, the wafer is passed through the furnace at an equal rate in either the uniform heating area at the center of the furnace or the non-uniform heating area at the end of the furnace. The inventor further clarified that sufficient heating in the soaking area cannot be achieved due to the continuous movement at a high speed.

[Object of the Invention] An object of the present invention is to provide a heat treatment apparatus that can perform uniform processing.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Summary of the Invention] A brief overview of typical inventions disclosed in this application is as follows.

That is, the heat treatment apparatus has a structure that includes a workpiece transfer mechanism that sequentially transports the workpiece from one direction of the furnace body to the other and stops the workpiece for a predetermined period of time in the soaking area within the furnace body. This makes it possible to continuously process the object to be processed, and to efficiently perform the heat treatment in the soaking area, thereby making it possible to perform uniform treatment.

[Example] Fig. 1 (al to f11 are explanatory diagrams sequentially showing the transport operation of a heat treatment apparatus according to an embodiment of the present invention, Fig. 2 is a schematic diagram showing the entire heat treatment apparatus, and Fig. 3 is a furnace body. It is a sectional view showing the inside of.

The heat treatment apparatus l of this embodiment is for heat treating wafers 2 (see FIG. 3) used for manufacturing semiconductor devices at a predetermined temperature, and includes a cylindrical furnace body 3 extending in the horizontal direction. and a heater 4 provided around the furnace body 3, and the heater 1 ensures that the inside of the furnace body 3 is always maintained at a predetermined temperature condition. Also,
A fluid supply pipe 5 is installed upward inside the furnace body 3, and the fluid supply pipe 6 has a plurality of fluid supply ports 5 as shown in FIG.
A is opened so that a fluid 6 such as nitrogen gas can be supplied into the furnace body 3. Further, a guide rail 7 is provided on the inner surface of the furnace body 3 and extends parallel to the axial direction.
A cartridge 8, which accommodates a plurality of wafers 2 as objects to be processed, is held inside the furnace body 3 while being suspended from the guide rail 7.

The furnace body 3 described above is made of, for example, quartz or the like, and if a wafer having a diameter of about 150 mm is to be processed, an inner diameter of the furnace body 3 of about 20 mm is sufficient.

The cartridge 8 is made of a material with good heat resistance such as quartz or fluorine resin, and has a plurality of support rods 8a formed with grooves (not shown) for vertically supporting a plurality of wafers 2 in parallel. , has a structure in which they are bonded by a bonding material (not shown).

A movable fork 9 is attached below inside the furnace body 3, and the cartridge 8 is moved inside the furnace body 3 while being placed on this movable fork 9. The fork 9 can move up and down, and can be stopped at a predetermined upper, middle, or lower position. In addition to the above-mentioned vertical movement, the mechanism allows continuous movement in the horizontal direction at a constant speed. Note that a recess 9a (FIG. 2) is formed in the center of the fork 9 over a length of about three cartridges, and the recess 9a (FIG. 2) is formed on the recess 9a only when the fork 9 is in the upper position. The structure allows the cartridge 8 on the cartridge 9a to be moved.

Here, to explain the function from the vertical position of the fork and the positional relationship of the cartridge, when the fork 9 is in the lower position, the cartridge 8 suspended on the guide rail 7 is in a state of being separated from the fork 9, and this The structure is such that the cartridge 8 does not move even if the fork 9 moves horizontally at this position. Further, when the fork 9 is in the middle position, the movement of the fork 9 enables horizontal movement of the cartridges suspended on the guide rail 7, except for the cartridge located on the recess 9a. Furthermore, when the fork 9 is located at the upper position, the cartridges, including the cartridge located above the recess 9a,
All the cartridges suspended on the guide rail 7 are movable by the movement of the fork 9.

Next, the operation of this embodiment will be explained based on FIG. 1.

In addition, in FIG. 1, the soaking area R in the furnace body 3 formed by the heater 4 is divided into a first zone R1 and a second zone R2 for convenience.

First, when the inside of the furnace body 3 is heated to a predetermined temperature condition by the heater 4, as shown in FIG.
is supplied to the inside of the furnace body 3.

In this way, with the inside of the furnace body 3 in a predetermined atmosphere, the cartridge A with a plurality of wafers 2 to be processed erected is placed on the fork 9 as shown in FIG. Supplied. At this time, the fork 9 is in the middle position, and while in this middle position, the fork 9 moves horizontally, and the cartridge A placed at f2 is moved to the position just before the soaking area R by the heater 4 ( Figure 1 (b
)). Next, the fork 9 rises to the upper stage position and places the cartridge A in the soaking area R.
((C) in the same figure). Thereafter, the fork 9 descends to the lower stage, moves back in the horizontal direction, and further rises to reach the middle stage position and return to the initial position (FIG. 4(d)).

At this position, when a new cartridge B is now supplied onto the fork ((el) in the same figure), the cartridge B is moved to a position just before the soaking area by the heater by the action of the fork ((el) in the same figure). (fl) At this time, the cartridge A in the first zone R1 of the soaking area R is suspended on the guide rail 7 above the recess 9a even if the fork 9 moves horizontally at the middle position, and the fork 9 Since it is in a non-contact state, its position does not move.

Next, the fork 9 rises to the upper stage and moves further in the horizontal direction, transferring the cartridges A and B (Fig.
In this way, the cartridge B placed immediately before the soaking area R is transferred to the first zone R1,
Cartridge A in the first zone R1 is transferred to the second zone R2. Next, the fork descends to the lower stage and returns to the initial position again by the same operation as described above ((h) in the same figure). At this time, when the fork returns to the middle position, among the cartridges A and B in the soaking area R, the cartridge A in the second zone R2 comes into contact with the fork 9, while the cartridge A in the second zone R2
Since the cartridge B is located on the recess 9a, it is out of contact with the fork 9.

Therefore, at this initial position, when a new cartridge C is supplied and the fork moves horizontally, only the cartridge A is carried out of the furnace body (FIG. 0) to (ri).

As described above, the cartridges A to C sequentially move within the furnace body 3, and the heat treatment of the wafers accommodated in the cartridges A to C is completed.

According to this embodiment, as described above, each cartridge is heat-treated in each zone R1, R2 within the soaking area R for a certain period of time, so that the cartridge is heat-treated within the heating conditions. Compared to a heat treatment apparatus that moves objects continuously at a constant speed, uniform processing can be achieved more efficiently.

[Effects] (1) A heat treatment equipment structure equipped with a workpiece transfer mechanism that sequentially transports the workpiece from one direction of the furnace body to the other and stops the workpiece for a predetermined period of time in a soaking area within the furnace body. By doing so, it is possible to continuously process the object to be processed, and also to efficiently perform the heat treatment in the soaking area, thereby achieving uniform treatment.

(2) With the fil, when a semiconductor wafer is used as an object to be processed, the yield of the wafer can be improved and a highly reliable semiconductor device can be efficiently provided.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that the present invention is not limited to the Examples and can be modified in various ways without departing from the gist thereof. Nor.

For example, the heater is not limited to the block heater described in the embodiment, but may be a lamp heater such as a halogen lamp.

Further, the means for transferring the object to be processed is not limited to the fork structure of the embodiment.

Alternatively, only the object to be processed may be transported horizontally (or vertically).

[Field of Application] In the above description, the invention made by the present inventor was mainly applied to the field of application, which is the so-called heat treatment of wafers. This is an effective technique when applied to

[Brief explanation of drawings]

Figures 1 (al to (1)) are diagrams sequentially explaining the transport operation of a heat treatment apparatus according to an embodiment of the present invention, Figure 2 is a schematic diagram showing the entire heat treatment apparatus according to the embodiment, and Figure 3 is a diagram showing the implementation. It is a sectional view showing the inside of the furnace body of the heat treatment apparatus of the example. 1... Heat treatment apparatus, 2... Wafer, 3... Furnace body, 4
...Heater, 5...Fluid supply pipe, 5a...Fluid supply port, 6...Fluid, 7...Guide rail, 8...
Cartridge, 9...Movable fork (fork), R
... soaking area, RI... first zone, R2... second zone. Figure 1 □ (1)! +1 H-C4 1st figure' (f) I I 1 1st M 2nd figure

Claims (1)

[Claims] 1. A heat treatment apparatus comprising a furnace body extending in the horizontal direction and a heating mechanism provided around the furnace body, the furnace body being exposed from one direction to the other. A heat treatment apparatus comprising a workpiece transfer mechanism that sequentially transports the workpiece and stops the workpiece for a predetermined period of time in a soaking area within a furnace. 2. The heat treatment according to claim 1, wherein the object to be processed is a semiconductor wafer, and the semiconductor wafers are transported in a furnace while being housed in a jig in units of a plurality of semiconductor wafers. Device. 3. The heat treatment apparatus according to claim 1, wherein the object to be treated is transferred by a fork provided movably in the vertical and horizontal directions within the furnace body.