JPH0773103B2 - Semiconductor heat treatment structure - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat holder, a furnace wall material and other structures which are disposed between a heating zone and a non-heating zone of a heat treatment apparatus for semiconductor manufacturing and which keeps heat and heat in the heating zone. .

[0002]

2. Description of the Related Art For example, as shown in FIG.
A quartz glass furnace tube 2 surrounding 1 is configured so that a semiconductor wafer 4 can be housed via a supporting jig 3, and the heating means
While the semiconductor wafer 4 mounted on the support jig 3 is heated to a predetermined temperature range by 1 and controlled, a reaction gas or an inert gas is flown to the surface area of the semiconductor wafer 4 to oxidize and diffuse the surface area of the semiconductor wafer 4. A heat treatment apparatus for performing various heat treatments such as vapor phase growth and annealing is known, and in this kind of heat treatment apparatus, it is possible to prevent variations in thickness and impurity concentration distribution of a thin film formed or implanted in the surface region of the wafer 4. In order to
A quartz glass heat retainer 5 is arranged between the heating area A in the furnace tube 2 and the opening end side of the furnace tube 2 to equalize the space temperature for heat treatment of the wafer 4 and to surround the furnace tube 2 around it. The heating means 1 is placed above the heat holder 5 and
By making 5 function as a heat insulating material, high temperature is prevented from propagating to the O-ring 6 and other sealing parts provided on the open end side of the furnace tube 2. In addition, such a heat retaining body 5 is generally configured by enclosing a long-fiber-shaped quartz glass wool 5b in a sealed cylindrical quartz glass body 5a.

[0003]

However, since the heat holder 5 having the above-mentioned structure has a structure in which the glass wool 5b is simply enclosed in the closed space, when the heat holder 5 is used in the heating furnace, A pressure load is applied to the inside of the cylindrical body 5a, and the heat holder 5 is surrounded by the heating tube 1 surrounding the furnace tube 2 above.
Since the upper surface side is always exposed to a high temperature by radiant heat from, the gas (air) in the sealed cylindrical body 5a is thermally expanded and the pressure load is further strengthened, and the cylindrical body 5a is destroyed. It may end up.

In order to eliminate such drawbacks, conventionally, ribs, glazing and other reinforcing rods have been mounted in the cylindrical body 5a,
We are trying to improve the pressure resistance, but wafer 4
As the furnace tube 2 becomes larger due to the larger diameter, the heat holder 5 also becomes larger in diameter, and the pressure resistance decreases accordingly.Therefore, a large number of reinforcing rods must be provided in a geometric progression. No
This leads to a complicated manufacturing work of the heat carrier 5 and a large increase in the manufacturing cost.
When the diameter is increased to about 0 mm, it is extremely difficult in terms of design and manufacturing to provide a large number of reinforcing rods so that the pressure resistance under vacuum and at high temperature can be smoothly satisfied. It was not possible to manufacture the heat carrier 5 of.

As a result, even if the furnace tube 2 is increased in size due to the increase in the diameter of the wafer 4, the heat retaining member 5 cannot be increased in size correspondingly, and thus the furnace tube 2 is
Wafers inside 4 The heating temperature from the heat treatment space is
It escapes from the gap between the inner wall surface of the furnace tube 2 and the heating temperature of the wafer 4 heat treatment area A, and it cannot completely prevent the high temperature from propagating to the seal part on the opening end side of the furnace tube 2. The problem was derived.

In view of the above-mentioned drawbacks of the prior art, the present invention provides a heat retainer 5 and other structures having high pressure resistance enough to withstand a large diameter while sufficiently satisfying heat insulation and heat retention. With the goal. Another object of the present invention is to provide a structure having heat insulating properties, heat retaining properties and high pressure resistance, which is suitably used as the heat retaining member 5 or a furnace wall material of a heating furnace.

[0007]

According to the present invention, as shown in FIG. 1, a structure 30, which is preferably used as a heat retaining member or a furnace wall material of a heating furnace, has a large number of minute spaces 31a therein. Quartz glass plastic body 31, in other words, the quartz glass plastic body
31 is not formed of a flexible member such as glass wool 5b, but by heating quartz fine powder in a vacuum furnace, for example, a large number of minute spaces 31a such as a foam glass body.
And a hard quartz glass thin film, which is itself formed inside, is formed of a plastic body which is stretched in a mesh shape in the vertical and horizontal directions, and the plastic body is used as a core body of the structure.

In this case, the minute space 31a exists as a closed cell, an open cell, or an open void, but most of them all need to exist under a reduced pressure or a vacuum at a temperature of 1300 ° C. or lower.

The structure 30 can be used as the plastic body 31 in which the minute space 31a is exposed on the surface, but the surface side of the quartz glass plastic body 31 is concealed by the transparent glass layer 32. However, it is preferable that the transparent glass layer 32 is interposed between the heating region A and the quartz glass plastic body 31.

The transparent glass layer 32 is formed as a structure by forming a thin transparent quartz glass layer 32 only on the surface layer by post-processing such as rubbing the outer peripheral surface of the core with a burner. Alternatively, the structure may be formed by heating fine quartz powder in a quartz glass container in a vacuum furnace and integrally welding with the quartz container.

[0011]

According to the present invention, the structure 30 used in the heat treatment apparatus such as the heat holder 5 and the furnace wall is made of the quartz glass plastic body 31 having a large number of minute spaces 31a therein, in other words, as shown in FIG. Since it is formed of a fine mesh-shaped plastic body having a minute space 31a inside, it naturally has heat retention and heat insulation properties, and the mesh-shaped quartz glass thin film functions as a rib-like or scuffing-like reinforcing material, Has high withstand voltage.

Further, in the present invention, if the minute space 31a is used while being exposed on the surface, impurities and impure gas existing in the minute space 31a during the manufacturing process of the semiconductor wafer 4 are led out to the outside, resulting in a product defect. May occur. Therefore, in a preferred embodiment of the present invention, the surface of the quartz glass plastic body 31 is covered with a thin film or a transparent glass layer 32 having a predetermined thickness, and the heating area A and the quartz glass plastic body 31 are covered by the transparent glass layer 32. By blocking the gap, the risk of product defects is eliminated, and the transparent glass layer 32 also functions as a reinforcing layer, further improving the pressure resistance. Also, the minute space 31a
Exists in a reduced pressure or vacuum state at least at 1300 ° C or lower to improve adiabatic heat retention and also
It is possible to prevent thermal expansion of the gas existing inside 31a, further improve the pressure resistance, and prevent the impure gas from being discharged to the outside.

[0013]

Embodiments of the present invention will now be illustratively described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative positions and the like of the components described in this embodiment are not intended to limit the scope of the present invention thereto, but are merely examples, unless otherwise specified. Not too much. Figure 1
2 shows an apparatus in which the heat holder 30 of the present invention is incorporated in the heat treatment apparatus having the vertical structure of FIG. 2, and the difference from the prior art will be mainly described, the lower part of the furnace tube 2 will be a base. 7 Position the heat holder 30 installed on the top, and on the upper surface of the heat holder 30,
A supporting jig 3 in which semiconductor wafers 4 are arranged in a row is placed, and a heating means 1 is surrounded around a furnace tube 2 in which the supporting jig 3 is located, and the semiconductor wafer 4 can be heat-treated by a known means. To configure.

The heat holder 30, which is the subject matter of the present invention, is formed of a quartz glass plastic body 31 formed inside and a surrounding body 32 made of transparent quartz glass surrounding the plastic body 31.
Next, the procedure for manufacturing the quartz glass plastic body 31 will be described. First, in the quartz crucible having an opening at the upper side and having the same shape as the surrounding body 32 and only a large height, quartz fine powder is mixed with carbon powder or other foaming promotion. By performing foaming acceleration treatment such as mixing of the agent and putting it in, and heating in a vacuum furnace at a temperature of around 1300 to 1800 ° C, there are many depressurized microspaces 31a inside, and quartz thin film 31b is stretched vertically and horizontally. The so-called foam glass-like quartz glass plastic body 31 is formed. (Fig. 3 (A) (B)
(See (C))

At this time, the quartz fine powder is subjected to a foaming accelerating treatment, for example, by mixing water together with carbon powder to make it into a mud state, and by heating it, a glass-like foam having a large number of depressurized fine spaces 31a is formed. The quartz glass plastic body 31 can be formed, which is preferable. Then, the quartz glass plastic body 31 formed in this way is heated by the heating, the surface thereof is integrally welded to the quartz crucible, and the volume is reduced, so that the upper portion of the reduced crucible is cut, A lid 32a is welded to the upper surface of the quartz glass plastic body 31, and the outer periphery of the quartz glass plastic body 31 is surrounded by a surrounding body 32.

As described above, in the above-described embodiment, the crucible is also used as the surrounding body 32. However, without adopting such a constitution, the quartz glass plastic body is formed in the carbon crucible.
After forming 31, the surface of the quartz glass plastic body 31 taken out from the crucible can be blown with a burner or the like to form a thin transparent quartz glass layer only on the surface layer later. .

According to such an embodiment, since the foam glass-like quartz glass plastic body 31 contained in the heat retaining body 30 itself has pressure resistance, even if the heat retaining body 30 has a large diameter, It can be formed by one member, and the effects described in the above-described embodiment can be achieved more smoothly. Since the heat retaining body 30 as described above can be formed in any shape, it can be used not only as the heat retaining body 5 but also as a furnace wall attached around the inner wall surface of the heating furnace.

[0018]

[Effect] As described above, according to the present invention, it is possible to provide a heat retainer or other structure having a high pressure resistance enough to withstand a large diameter while sufficiently satisfying heat insulation and heat retention. Not only can the structure be suitably used as the heat retainer and the furnace wall material of the heating furnace. It has various remarkable effects.

[Brief description of drawings]

FIG. 1 is an overall front sectional view showing a heat treatment apparatus having a vertical structure according to an embodiment of the present invention.

FIG. 2 is an overall front sectional view showing a conventionally known heat treatment apparatus.

FIG. 3 is an enlarged view showing an internal configuration of a plastic body used in the present invention.

[Explanation of symbols]

 30 Structure 31 Quartz glass plastic 31a Micro space 32 Transparent glass layer A Heating area

Claims (3)

[Claims] 1. A structure, which is arranged between a heating zone and a non-heating zone of a heat treatment apparatus for semiconductor manufacturing and performs heat insulation and heat insulation of the heating zone, by heating fine quartz powder in a vacuum furnace, a large number of quartz fine powders are internally provided. Structure for a semiconductor heat treatment apparatus, characterized in that it has a reduced pressure or vacuum micro space, forms a plastic body in which a quartz thin film is stretched vertically and horizontally, and uses the plastic body as a core body of the structure body. 2. The structure for semiconductor heat treatment according to claim 1, wherein the outer peripheral surface of the core body is a structure body in which a thin transparent quartz glass layer is formed only on the surface layer. 3. The structure for heat treatment of semiconductor according to claim 1, wherein the quartz fine powder is filled in a quartz glass container, heated in a vacuum furnace, and integrally fused with the quartz container. body