JP2933469B2 - Heat treatment equipment - 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 treatment apparatus for semiconductor wafers and the like, and more particularly to a heat treatment apparatus suitable for short-time heat treatment of one or several semiconductor wafers.

[0002]

2. Description of the Related Art A conventional apparatus of this kind is disclosed in
As described in JP-A-81921, there is a lamp heating apparatus for heating one semiconductor wafer to a predetermined temperature in a short time by a heating source constituted by a halogen lamp. However, this lamp heating apparatus has a problem that the lamp life is short and the lamp is significantly deteriorated when continuously heated, so that the semiconductor wafer cannot be heat-treated continuously and stably.

In order to solve the above problems, there is a heat treatment apparatus using a metal heating element as a heating source as described in Japanese Patent Application Laid-Open No. 2-216820. This apparatus includes an inner vessel for covering a metal heating element with a heat insulating material and heat-treating a semiconductor wafer therein, and a heat equalizing tube for uniformizing radiant heat of the metal heating element. The inner container is of a vertical type, and has an opening through which a semiconductor wafer is taken in and out, and a wafer insertion jig on which the semiconductor wafer is placed is inserted into the inner container heated to a predetermined temperature from the lower opening. Then, heat treatment is performed for a desired time. Also, in order to make the temperature difference in the semiconductor wafer surface (the temperature difference between the outer peripheral portion and the central portion) uniform, the two jigs are almost parallel to the insertion jig for introducing the semiconductor wafer into the inner container. In addition, a partition plate is provided to partition between the two semiconductor wafers.

[0004]

However, the prior art having such a structure has the following problems. That is, to heat and cool a semiconductor wafer,
It is necessary to introduce and remove the insertion jig on which the semiconductor wafer is placed into the inner container heated to a predetermined temperature, and move it.
Since it is difficult to move the insertion jig on which the microfabricated semiconductor wafer of brittle material is mounted at a high speed, a temperature difference occurs in the surface of the semiconductor wafer when the semiconductor device is introduced and removed from the inner container, and the semiconductor device is formed on the semiconductor wafer. However, there is a problem that the characteristics of the semiconductor elements vary, and crystal defects easily occur in the semiconductor wafer.

The present invention has been made in view of such circumstances, and has as its object to provide a heat treatment apparatus capable of reducing the in-plane temperature difference of a semiconductor wafer.

[0006]

The present invention has the following configuration in order to achieve the above object. That is, the heat treatment apparatus according to the present invention is a heat treatment apparatus for thermally processing a semiconductor wafer, and an outer container to form a heating space therein, is provided inside of the outer container, the semiconductor wafer
It can be stored and opened for loading and unloading semiconductor wafers.
An inner container having a mouth, and a semi-conductive member inside the inner container.
A substrate support for supporting the body wafer, and
Provided on the substrate support inside the inner container.
Therefore, a heater for heating the supported semiconductor wafer,
It is disposed between the heater and the inner container so as to be openable and closable.
The surface on the heater side is a mirror surface and
Surface is to comprising: the shutter treated blackening, the.

[0007]

The operation of the present invention is as follows. That is,
When the semiconductor wafer is introduced into the inner container, it is arranged to be openable and closable between the heater and the inner container.
The surface is a mirror surface and the surface on the inner container side is blackened.
The closed shutter closed. In this state, a semiconductor wafer is introduced into the inner container. After introducing the semiconductor wafer to the predetermined position inside the inner container, open the shutter
The semiconductor wafer is heated by the heater for a predetermined time.
When the heating process is completed, the shutter is closed. In this state, the semiconductor wafer is taken out of the inner container.

[0008]

An embodiment of the present invention will be described below with reference to the drawings. <First Embodiment> FIGS. 1 and 2 are cross-sectional views showing a schematic configuration of an apparatus according to an embodiment of the present invention. In particular, FIG. 1 is a vertical cross-sectional view, and FIG. FIG.

In FIG. 1, reference numeral 10 denotes an outer container forming a heating space. The outer container 10 includes an upper reflecting plate 10a provided at an upper portion, two side plates 10b having through holes for inserting and removing a shutter 50 described later on a side surface, a lower reflecting plate 10c provided at a lower portion, and a semiconductor wafer. Is closed by a side plate 10d provided on the introduction / removal side of and a side plate 10e opposed thereto.
The outer container 10 is formed of, for example, an aluminum alloy or the like, and has a cooling pipe 11 through which a cooling medium such as water flows inside each plate.
Many are buried. The upper reflector 10a and the lower reflector 10c are arranged on the heating space side in order to reflect radiant heat from the heater unit 20 and prevent deterioration of the reflectance.
u plating is applied.

[0010] The upper and lower inner surfaces of the side plate 10b
Heater units 20 for radiating radiant heat are installed in parallel with each other, and the upper and lower portions of each heater portion 20 , that is, the outer container 10
Between the inside of the container and the heater section 20, and inside the outer container 10.
Between the shutter 50 and the heater unit 20 in the closed state at
Between them, a convection prevention plate 25 made of quartz for preventing fluctuation of the temperature distribution due to convection is provided. The heater unit 20 includes a plurality of regions (five regions as an example in the present embodiment) in order to make the temperature distribution in the inner container 30 uniform.
And each is independently controlled.

As shown in FIG. 3, a heater portion 20 is provided with a heater support rod 21 formed of high-purity alumina or the like in a round bar shape whose insulation property does not decrease even at a high temperature, and an electrothermal material such as an Fe-Cr-Al alloy. The plate-like heater 22 formed in the above is braided in a wave shape. The plate-like heaters 22 are electrically connected to each other via a welded portion 23 to which each end is connected, and each heater 22 is separated by an insulating plate 24 such as alumina.

The heater section 20 is not limited to the one shown in FIG. 3, but may be, for example, as shown in FIG.
Heater 22a made of the same material in place of
May be used as the heater unit 20.

An inner container 30 made of quartz is provided at an intermediate position between the upper and lower heater sections 20. An inlet 30a for allowing a semiconductor material gas such as N ₂ , O ₂ and silane to flow at a predetermined flow rate is provided at the front end of the inner container 30.
Exhaust port 30b for discharging gas from inflow port 30a
And an opening 30c for introducing and removing the semiconductor wafer W.

In order to introduce / remove the semiconductor wafer W into / from the inner container 30, the opening 30c of the inner container 30 is required.
Is used. The substrate support 40 is formed of quartz glass or the like, and the semiconductor wafer W
Is provided with a circular frame 42 to which several claws 41 are attached so as to abut against the semiconductor wafer W in order to stably hold the horizontal. On the opening side of the inner container 30 of the substrate support 40,
There is a support rod 43 made of quartz glass, which is connected to a lid 44 that closes the opening 30 c of the inner container 30. The substrate support 40 is driven by a transport mechanism (not shown).

A pair of upper and lower shutters 50 in which cooling pipes 11 are buried are mounted in two through holes provided in each side plate 10b in the same manner as the upper reflector 10a of the outer container 10 so as to be insertable and removable. a pair of shutters 50 are opposed to the side plates 10b. The surface of each shutter 50 on the heater section 20 side is mirror-finished so as to reflect radiant heat, and the surface on the inner container 30 side is finished by blackening processing to absorb the heat of the semiconductor wafer W.

The upper and lower shutters 50 of each side plate 10b are cantilevered by an L-shaped movable member 51 so as to be parallel to each other at an upper position and a lower position of the inner container 30.
Each movable member 51 is swingably attached to a fixed rail 52 and connected to the rods of two cylinders 53. When the respective cylinders are contracted and driven, two sets of opposing shutters 50 come into contact with the heating space at the center.

Next, the operation will be described with reference to FIG. FIG. 5 is a diagram illustrating the relationship between the temperature of the semiconductor wafer W in the inner container 30 and the temperature of the heater unit 20 and the time in the heating / cooling processing by the heat treatment apparatus according to the present embodiment. The temperature was measured using a thermocouple attached to the surface of the semiconductor wafer W supported in contact with the substrate support 40 in the inner container 30 and a thermocouple controlled to be divided into five portions of the heater section 20.

First, with the cylinder 53 contracted, that is, with the shutter 50 closed, the temperature of the heater section 20 is set to 1000 ° C.

With the shutter 50 closed, the substrate support 40 on which the semiconductor wafer W is placed is introduced through the opening 30c of the inner container 30, moved at a desired speed, and stopped at the processing position. During this time, the radiant heat from the heater section 20 is blocked and absorbed by the shutter 50, so that the semiconductor wafer W
Is hardly heated.

The cylinder 53 is driven at a high speed (for example,
(Approximately 0.1 second), the shutter 50 is opened , and the substrate support 40 is
A state where the radiant heat is applied to the supported semiconductor wafer W (heating state) is set. This is the state where the elapsed time is 0 minutes in FIG. In this state, the radiant heat is absorbed by the inner container 30, the semiconductor wafer W, and the like, and the temperature of the heater unit 20 is temporarily lowered. However, since the heater section 20 is controlled, the temperature immediately returns to the set temperature. Semiconductor wafer W
Reaches a target temperature of 1000 ° C. rapidly (about 1 minute).

After the heating process has been performed for about 4 minutes, the cylinder 53 contracts at a high speed, thereby causing the shutter 50 to contract.
Is closed so that the semiconductor wafer W in the inner container 30 is not irradiated with radiant heat (cooling state). In this state, since the radiant heat is reflected by the mirror-finished surface formed on the heater section 20 side of the shutter 50, as opposed to when the shutter 50 is opened, the temperature of the heater section 20 is temporarily increased. On the other hand, when the radiant heat is shut off by closing the shutter 50, the semiconductor wafer W
Is rapidly cooled by the effect of the blackening process performed on the inner container 30 side.

Next, referring to FIG. 6, the temperature difference between the outer peripheral portion and the central portion of the semiconductor wafer W, which is the temperature difference within the wafer surface,
Apparatus according to the present invention and prior art JP-A-2-21682
Comparison is made with the heat treatment apparatus described in Japanese Patent Publication No.

In the figure, Conventional 1 is a case where a partition plate for partitioning a semiconductor wafer is not provided in the above-mentioned conventional apparatus, and Conventional 2 is a case where a partition plate is provided. In addition,
In the conventional example, since only data at the time of heating is described, data at the time of cooling is not drawn. The set temperatures (temperatures of the semiconductor wafer W) are all 1000 ° C.

In the conventional example having no partition plate for partitioning a semiconductor wafer as shown in the conventional example 1, the temperature difference within the wafer surface exceeds 100 ° C. at the maximum. In addition, even when the partition plate is provided as shown in the conventional example 2, the temperature exceeds 60 ° C. On the other hand, in the heat treatment apparatus according to the present invention, the maximum temperature is about 15 ° C. during heating and cooling.

<Second Embodiment> In the first embodiment, the apparatus is for processing one semiconductor wafer. However, two semiconductor wafers may be processed. Hereinafter, description will be made with reference to a longitudinal sectional view showing a schematic configuration of FIG.

In the figure, the same reference numerals as those of the first embodiment shown in FIG. 1 denote the same components, and a description thereof will be omitted. Code 40
Reference symbol a denotes a substrate support that is introduced and taken out of the inner container 30. In the substrate support 40a, two slits are provided in the longitudinal direction on the inner surface of a quartz glass prism so that two semiconductor wafers W can be placed and held.

In each of the above embodiments, a pair of upper and lower shutters 50 is provided between each heater unit 20 and the inner container 30 because the heater units 20 are disposed above and below the inner container 30, respectively. In the case where the shutter 20 is disposed on one of the upper and lower sides, only one shutter 50 needs to be provided between the heater section 20 and the inner container 30.

In the embodiment, two sets of the shutters 50 are arranged to face each other in order to minimize the time required for opening and closing the shutters 50. However, the present invention is not necessarily limited to this, and is provided on one side plate. You may comprise only one set of shutters.

The drive mechanism of the shutter is not limited to the slide mechanism as in the embodiment, but may be a mechanism that drives the shutter to swing, and the drive mechanism can be variously changed.

Further, in the above embodiment, the horizontal heat treatment apparatus for introducing / removing the semiconductor wafer W from the horizontal direction is used. However, a vertical heat treatment apparatus for introducing / removing the semiconductor wafer W from the vertical direction may be used.

As is apparent from the above description, according to the present invention, between the inner container to heat <br/> over data and the semiconductor wafer which is provided inside the outer container forming the heating space is accommodated The heater side surface is mirror-like and the inner container side
Shutter whose surface is treated blackening is provided, this Shah
The radiator can quickly and uniformly irradiate and shut off the radiant heat to the semiconductor wafer, so that the in-plane temperature difference of the semiconductor wafer can be extremely reduced, and the characteristics of the semiconductor elements formed on the semiconductor wafer vary. And crystal defects generated in a semiconductor wafer can be minimized.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a schematic configuration of a heat treatment apparatus according to a first embodiment.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a perspective view illustrating a schematic configuration of a heater unit.

FIG. 4 is a perspective view showing a schematic configuration of a modification of the heater section.

FIG. 5 is a diagram provided to explain a heating / cooling process in the heat treatment apparatus according to the first embodiment.

FIG. 6 is a diagram showing an in-plane temperature difference of a semiconductor wafer in a heating / cooling process in the heat treatment apparatus according to the first embodiment.

FIG. 7 is a longitudinal sectional view illustrating a schematic configuration of a heat treatment apparatus according to a second embodiment.

[Explanation of symbols]

 Reference Signs List 10 outer container 10a upper reflector 10b lower reflector 11 cooling pipe 20, 20a heater 21 heater support rod 22 plate heater 22a coil heater 25 convection prevention plate 30 inner container 40, 40a ... Substrate support 50 ... Shutter 51 ... Movable member 52 ... Fixed rail 53 ... Cylinder W ... Semiconductor wafer

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01L 21/324 H01L 21/22 501 H01L 21/22 511

Claims (1)

(57) [Claims] 1. A heat treatment apparatus for a semiconductor wafer to heat treatment, the outer container forms a heating space therein, is provided inside of the outer container, capable of accommodating a semiconductor wafer
And an opening for taking in and out the semiconductor wafer.
And a substrate for supporting a semiconductor wafer inside the inner container
A support , provided inside the outer container, and inside the inner container;
The semiconductor wafer supported by the substrate support
A heater to be heated , disposed to be freely openable and closable between the heater and the inner container,
The surface on the heater side is a mirror surface and the inner container side
A heat treatment apparatus , comprising: a shutter having a surface blackened .