TWI579216B - Fixed pin for fixed wafer in crystal boat and its manufacturing method - Google Patents

Description

Fixed wafer fixed wafer in wafer boat and manufacturing method thereof

The present invention relates to a fixing pin for fixing a wafer to a wafer boat during wafer processing and wafer processing through a processing apparatus, and a method of manufacturing such a fixing pin.

The boat can be made of CFC, graphite, ceramic, metal, or a combination of the above. In order to be able to fix the wafer without being affected by force during the processing and transport of the wafer boat, the wafer is usually inserted in a standing manner on a fixed pin similar to a mushroom distributed on a flat surface. Depending on the size of the wafer, each wafer typically requires two or three fixed pins.

These fixing pins are also made of CFC, graphite, ceramic, or metal, and are connected to the boat via a plug connection, a screw connection, or a clamp connection. Because wafers must be transported through a variety of different processing equipment, graphite can be eroded by certain processing effects. Eroded graphite members are less resistant and therefore more susceptible to wear, resulting in frequent replacement of worn pins.

In order to provide better protection for the fixing pins during processing, an additional coating can be applied to the boat and the fixing pins. For example, carbon coating or graphite coating. This coating is formed by a heated chemical vapor deposition process in a processing chamber. Another possible way is to form this coating on the processing tool on which the boat is placed.

The coating of the boat is formed by plasma assisted chemical vapor deposition (PECVD). in At the same time, the fixing pin can also be coated. However, since the fixing pin is still subject to a certain degree of wear during the mounting and dismounting of the wafer, the fixing pin must be replaced periodically. Although the above-mentioned coating can improve the abrasion resistance, it is still insufficient for a long-term continuous production operation.

The object of the present invention is to provide a fixing pin for fixing a wafer to a wafer boat during wafer processing and wafer processing through a processing device, and the fixing pin must have good wear resistance, and the present invention further A method of manufacturing such a fixing pin is proposed.

In order to achieve the above object, the fixing pin proposed by the present invention is coated with a layer of tantalum carbide at least on the surface and a region below the entire surface, or is formed of tantalum carbide, wherein the tantalum carbide is converted from graphite of a fixed pin.

The fixing pin of the present invention has the advantage of having high abrasion resistance.

According to a further development of the invention, the fixing pin having the surface converted from tantalum carbide has the same dimensional stability and the same size as the fixing pin made entirely of CFC or graphite, because during the material conversion process There is no material growth.

Therefore, it is possible to directly replace the fixing pin made of worn CFC or graphite with a fixing pin having a ruthenium carbide coating.

In order to achieve another object of the present invention, the present invention provides a method of manufacturing a fixing pin by heating a conversion pin made of CFC or graphite in a protective gas atmosphere containing helium vapor, in the process. At least the surface of the pin can be converted to tantalum carbide.

The heat conversion process is preferably carried out in a vacuum furnace/protective gas furnace or a muffle furnace which can be operated under an overpressure.

In addition, the heating conversion process is preferably in the temperature range of 1200 ° C to 2200 ° C Row.

Another embodiment of the invention features hydrogen or argon as the shielding gas.

An improved form of the invention is the heating and evaporation of pellets containing cerium to produce hydrazine vapor.

The method of the invention enables complete conversion of the graphite surface of the pin or (depending on time) to tantalum carbide.

The special advantage of the method according to the invention is that it is possible to produce a fixing pin which is very resistant to wear, and the size of the fixing pin remains completely unchanged during the conversion process, so that it can be stored as a replacement part, that is to say without difficulty Replace the general fixing pin made of graphite or CFC with the fixing pin of the present invention.

1‧‧‧ wafer

2‧‧‧Frame components

3‧‧‧ Opening

4‧‧‧fixed pin

5‧‧‧Ontology

6‧‧‧ end face

7‧‧‧stops

8‧‧‧Side/groove

The contents of the present invention will be further described below in conjunction with the drawings and embodiments. Among them: Figure 1: A perspective view of a boat.

Figure 2: Different embodiments of mushroom shaped fixing pins.

Fig. 1 shows a perspective perspective view of a wafer boat 1 in which the boat 1 is composed of a plurality of frame members 2 arranged in a row and connected to each other. Each of the frame members 2 has an opening 3 for receiving a replaceable mushroom-shaped fixing pin 4, wherein the fixing pin 4 is tasked with accommodating and fixing a wafer not shown in the drawings. The wafer referred to herein may be a slab, a glass sheet, or other flat element.

As shown in Fig. 2, the mushroom-shaped fixing pin 4 made of graphite or CFC can have a very wide variety of shapes. Overall, all the fixing pins 4 are made of a cylindrical body 5 It is constructed in which both end faces 6 of the body 5 have protruding stoppers 7, and the stoppers 7 are provided with undercuts or grooves 8 for accommodating the wafer. The thickness of the cylindrical body 5 is equal to the thickness of the frame member 2. If the fixing pin is inserted into the corresponding opening 3 of the frame member 2 and the body 5 is flush with the opening 3, the stopper 7 will protrude from both sides of the frame member 2, and thus on each side of the frame member 2 A wafer can be securely placed and the wafers are spaced a short distance from the surface of the frame member 2.

The surface of the fixing pin 4 and the region connected below the surface are composed of tantalum carbide, wherein the tantalum carbide is produced by the conversion process of the graphite of the fixing pin 4. This fixing pin 4 therefore has a particularly good abrasion resistance.

The fixing pin 4 having the ruthenium carbide coating has the same dimensional stability as the fixing pin made entirely of graphite or CFC because the material growth does not occur during the material conversion.

A great advantage of the invention is therefore that the worn fixing pins and/or the fixing pins made of CFC or graphite can be directly replaced with fixing pins having a ruthenium carbide coating.

The method of manufacturing the fixing pin 4 which is at least partially composed of tantalum carbide is to carry out a heating conversion process of the fixing pin 4 made of graphite or CFC at a temperature of 1200 ° C to 2200 ° C in a protective gas atmosphere containing helium vapor. During this heating conversion, at least the surface of the fixing pin 4 is converted into tantalum carbide. Evaporation of the cerium-containing pellets produces the necessary hydrazine vapor. This heating conversion process is carried out in a vacuum furnace/protective gas furnace or muffle furnace which can be operated under an overpressure.

Both hydrogen and argon are suitable as protective gases.

The method of the invention converts at least the surface of the graphite into tantalum carbide. Depending on the time, it is also possible to completely convert the graphite into niobium carbide.

4‧‧‧fixed pin

5‧‧‧Ontology

6‧‧‧ end face

7‧‧‧stops

8‧‧‧Side/groove

Claims (7)

A fixing pin for fixing a wafer to a wafer boat during wafer processing and wafer processing through a processing apparatus, the fixing pin being made of CFC or graphite, characterized in that at least on the surface of the fixing pin and connected to the entire surface The lower area is coated with a layer of tantalum carbide, which is converted from the graphite of the fixed pin. A fixing pin according to claim 1, wherein the fixing pin having the ruthenium carbide coating has the same dimensional stability and the same size as the fixing pin made entirely of CFC or graphite. A method of manufacturing a fixing pin according to the first aspect of the patent application, the fixing pin for fixing a wafer to a boat, wherein: a fixing pin made of CFC or graphite is carried out in a shielding gas atmosphere containing helium vapor The conversion process is heated, during which at least the surface of the pin is converted to tantalum carbide. The method of claim 3, wherein the heating conversion process is carried out in a vacuum furnace/protective gas furnace or a muffle furnace that can be operated under an overpressure. The method of claim 4, wherein the heating conversion process is carried out at a temperature ranging from 1200 °C to 2200 °C. The method of claim 3, wherein hydrogen or argon is used as the shielding gas. The method of claim 3, wherein the cerium-containing pellets are evaporated to produce hydrazine vapor.