JPS6345376A - Soft landing device - Google Patents

Abstract

PURPOSE:To improve throughput without generating the camber and crystal defects of wafers by disposing heating means adjacently to the advancing and retreating path of a quartz fork pipe. CONSTITUTION:A soft landing device 1 is connected to a diffusion furnace 3 and the quartz fork pipe 5 for putting in and out of wafers 18 is disposed therein. The quartz fork pipe 5 is fixed to a carrier 24 movable forward and backward on guide rails 22a.b. The heating means 10a and 10b are disposed adjacently to the advancing and retreating path of the quartz fork pipe 5. Electric heating wires, etc., far IR rays or microwaves, etc., are usable for the heating means 10a, 10b. After the wafers 18 are charged into a quartz boat 16, the heating means 10a, 10b are operated to heat the wafers 18 gradually. The wafers 18 are then allowed to cool by decreasing the calorific value of the heating means 10a, 10b gradually. The generation of the camber and crystal defects in the wafers is prevented by such device.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a soft landing device. More specifically, the present invention relates to a soft landing device in which a single stage of heat generating blade is disposed adjacent to the forward and backward movement path of the fork tube.

[Prior Art] A gas phase reactor using a horizontal reactor (e.g. CVD
In the thin film forming equipment, oxidation furnace, diffusion furnace, and dry etching equipment τ), a soft landing device with a quartz fork tube is used as the 11th stage for feeding wafers into the reactor and for taking the wafers out of the reactor. It is used.

Quartz has excellent physical and chemical properties, hardly deforms even when exposed to high temperatures, and has low thermal expansion.

Historically, pure products are relatively easy to obtain and have high chemical resistance (
, has high mechanical strength against temperature changes.

As a result, it has become one of the most expensive semiconductor manufacturing processes. It is preferably used in processes or equipment where particularly harsh conditions such as straw or corrosive chemicals are applied.

[Problems to be Solved by the Invention] The above-mentioned gas phase reactor generally performs temperature treatment. Therefore, the quartz fork tube in the conventional soft landing and franging equipment is
The wafers were being transported in a condition where the temperature inside the reactor was approximately 1,000 degrees Celsius, with a very large temperature difference.

Although the quartz fork tube itself is extremely resilient to temperature differences, the wafer, which is exposed to severe temperature differences along with the quartz fork tube, is extremely vulnerable to temperature differences.

When the wafer is rapidly heated or cooled, "warpage" occurs in the wafer 1 due to thermal stress, and crystal defects such as unripe lines occur.

In order to prevent "warping" and crystal defects from occurring, the temperature of the reactor must be lowered for each batch, or the quartz fork tube carrying the wafers must be moved in and out at a very slow speed.

However, it is not possible to improve the throughput of semiconductor manufacturing by lowering the temperature of the reactor for each batch or by transporting the quartz fork tube at a low speed.

[Object of the Invention] Therefore, an object of the present invention is to provide a soft landing device that can increase the throughput of semiconductor manufacturing without causing "warpage" or crystal defects in the wafer.

[Steps to Solve the Problems] In order to solve the above-mentioned problems and achieve the objects of the present invention, the present invention provides software for irradiating a quartz fork tube that can move forward and backward. In the landing equipment,
A soft landing device is provided, characterized in that a heat generating means is disposed adjacent to the forward and backward movement 11 of the quartz fork tube.

[Operations] As described above, in the soft landing device of the present invention, the heating means is disposed adjacent to the advancing and retreating path of the quartz fork tube.

Therefore, when taking a quartz fork tube in and out of a high-temperature reactor, the quartz fork tube is heated in the soft landing device to near the temperature inside the reactor, or the temperature inside the reactor is gradually brought down to room temperature. It can be made as low as 0.

Thus, the wafer placed in the quartz fork tube
The occurrence of warpage and crystal defects can be effectively prevented. As a result, the production yield of the l'-conductor element r can be increased.

In addition, with the conventional method of loading and unloading wafers from the reactor at an extremely slow speed, the next reaction process cannot be started until the loading and unloading is completed, but according to the present invention, the wafers are heated p-unevenly or slowly cooled in the soft landing device. As a result, the reactor is always kept ready to start a new reaction process. As a result, the throughput of semiconductor manufacturing can be dramatically improved.

[Embodiment Code] An embodiment of the present invention will be described in further detail with reference to the N side.

Figure 1 shows the side view 4I of the soft landing device of the present invention!
This is the essential diagram.

For convenience of explanation, the soft landing device of the present invention will be used for a diffusion furnace.

As shown in FIG. 1, the soft landing device 1 of the present invention is connected to a diffusion furnace 3. A quartz fork tube 5 is disposed within the soft landing device 1 for loading and unloading wafers into a furnace core tube 7 made of quartz.

The quartz fork tube 5 has guide rails 22a and 22b.
It is fixed to a carrier 24 that can move forward and backward on the top. The carrier 24 can be configured to be driven by an air cylinder or the like. The quartz fork tube 5 can be fixed to the carrier, for example, by tightening the retaining plate 26 with tightening rings 28a and 28b.

Furthermore, it is also possible to press a stopper 30 against the end of the tube. The stopper can be screwed onto the retainer plate.

A heating means tOa is provided adjacent to the forward and backward movement path of the quartz fork tube 5.
and 10b are arranged. As this heating means, for example, resistance heating means such as a heating wire, electromagnetic wave heating means such as far infrared rays or microwaves can be used.

The heating stage must be placed in a position that does not obstruct the path of advancement and retreat of the quartz fork tube. The heat generating means can be arranged at convenient positions above and below and/or left and right with respect to the forward and backward movement path of the quartz fork tube.

At least one heat generating stage may be provided, but four heat generating stages may be provided around the quartz fork tube. or,
It can also be constructed in the form of a tunnel so as to surround the entire periphery.

As long as it does not obstruct the forward and backward movement of the quartz fork tube, the heating means may be configured to be movable back and forth, left and right, or downward. Such a movable configuration of the heating means may be convenient for moving wafers into and out of the soft landing device or the reactor core tube.

A furnace mouth 9 of a furnace core tube 7 is opened at the joint between the soft landing device 1 and the diffusion device 3.

This furnace mouth 9 is opened and closed by a gate part 12. Furnace tube 7
is heated to a temperature of about 1000° C. by heaters 14a and 14b. A doping unit 20 is connected to the side of the furnace core tube 7 opposite to the furnace mouth.

Next, the specific operation of the soft landing device of the present invention will be explained.

The heating means 10a and 10b are provided by attaching a wafer 18 to a quartz diagonal jig or boat 16 in a half-cut portion of the quartz fork tube 5.
When charging and discharging, the battery is cooled to room temperature.

After charging the wafers 18 into the quartz boat 16, the heating stages 10a and lOb are activated to gradually heat the quartz fork tube, boat, and wafers.

Once these have been sufficiently p-uniformly heated to near the core temperature,
The gate portion 12 is opened, the carrier 24 is quietly and slowly advanced, and the quartz fork tube 5 is introduced into the reactor core tube.

Once the boat 16 has been transported to a predetermined position within the core tube, the quartz fork tube lowers the boat into that position and retreats. When the quartz fork tube is completely retreated to the outside of the reactor core tube, the gate portion 12 closes the reactor mouth 9. Thereafter, impurities are supplied from the doping unit 20 into the furnace tube, and a predetermined doping process is performed on the carried-in wafer.

Since quartz is strong against temperature differences, the empty quartz fork tube that has retreated into the soft landing device can be suddenly exposed to room temperature instead of being allowed to cool gradually by the heating means 10a and 10b.

Before the doping process for the wafer 18 is completed, the heating means 10a and 10b are activated to sufficiently heat the empty quartz fork tube 5 to near the core temperature. When the quartz fork tube 5 is sufficiently unevenly heated and the doping process is completed, the gate portion 12 is opened, the carrier 24 is quietly and slowly advanced, and the quartz fork tube 5 is introduced into the furnace core tube. Then, lift the quartz boat inside the reactor core tube and slowly and quietly carry it out of the reactor core tube.

When the quartz boat 16 reaches near the center of the heat generating means 10a and 10b, the quartz fork tube 5 stops retreating. At the same time, the gate section 12 is closed. Heat generation means 1
By gradually reducing the heat generation amount of 0a and 10b, the wafer on the quartz fork tube is allowed to cool very slowly. Heat generation M is reduced at a rate that maintains a temperature difference within a range that does not cause "warpage" or crystal defects in the wafer.

After the wafer is allowed to cool to around room temperature, the wafer 1 is removed from the soft landing device.

By connecting multiple soft landing devices to a single furnace core tube, the furnace core tube can always be maintained in a high-temperature heated state and doping processing can be performed continuously within the tube. That is, if the system is configured such that one soft landing device unevenly heats the wafer by t and the other soft landing device cools the wafer, continuous processing can be performed by +iJ.

The temperature control method for the heat generating means 10a and 10b is as follows:
A so-called auto profile method is preferred. This method uses a computer to determine the control amount for the temperature controller so that the temperature profile measured by the temperature sensor becomes a desired profile. At this time, the desired temperature profile and the corresponding control h1 are stored in the computer in advance. In this way, it is effectively possible to prevent "warpage" or crystal defects from occurring in the wafer when the wafer is heated or cooled.

Hereinafter, the soft landing device of the present invention will be conveniently used.
1. Although the soft landing device of the present invention has been described as being for use in a diffusion furnace, it is not limited to diffusion furnaces.
It can also be used in, for example, CVI (CVI) thin film forming equipment, oxidation furnaces, dry etching equipment, etc. where wafers are exposed to wafers and where the occurrence of "warpage" or crystal defects is expected.

[Effects of the Invention] As explained above, in the soft landing device of the present invention, the heat generating means is disposed adjacent to the advancing and retreating path of the quartz fork tube.

Therefore, when a quartz fork tube is taken in and out of a high-temperature reactor, the quartz fork tube is heated in the soft landing device to near the temperature inside the reactor, or the temperature inside the reactor is gradually brought down to room temperature. It can be lowered to F.

In this way, it is possible to effectively prevent "warpage" and crystal defects from occurring in the wafer placed on the quartz fork tube.

As a result, the manufacturing yield of ten conductor elements r can be increased.

Furthermore, in the conventional method of loading and unloading wafers from a reactor at an extremely slow speed, it is not possible to start the next reaction process until loading and unloading is completed, but according to the present invention, wafers are heated unevenly in a soft landing device. Alternatively, slow cooling can be performed, so that the reactor is always kept ready to start a new reaction process. As a result, 'Ji
The throughput of conductor manufacturing can be dramatically increased.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view of the soft landing device of the present invention. l... Soft landing 'Am, 3... Diffusion furnace,
5...Quartz fork tube, 7...Quartz furnace core tube, 9...
・The hearth. 10a and 10b...heating means, 12...gate portion. 14a and 14b... heating means, 16... quartz bow), 18... wafer, 20... doping unit. 22a and 22b...guide rail, 24...carrier, 26...retention plate, 28a and 28b...
Closing shell, 30...stopper

Claims (4)

[Claims] (1) A soft landing device having a quartz fork tube that can move forward and backward, characterized in that a heat generating means is disposed adjacent to the path of movement of the quartz fork tube. (2) The soft landing device according to claim 1, wherein the heat generating means is a heating wire heater. (3) The soft landing device according to claim 1, wherein the heat generating means is a far-infrared heater. (4) Claim 1 that the heating means is a microwave
Soft landing device as described in section.