KR100208623B1 - Quartz glass jig for the heat treatment of silicon wafers and method and device for producing the same - Google Patents

Abstract

The present invention is a combination jig for heat treatment of a silicon wafer comprising a mounting jig (JIG) on which a silicon (Si) wafer (WAFER) is placed and a supporting jig (JIG) for supporting the jig (JIG). Silicon wafer mounting jig (JIG) and the support jig (JIG) is formed of quartz glass, the jig (JIG) is a combination jig for heat treatment of silicon wafer, characterized in that configured to be combined via a silicon member. And to a method for producing the same.

The silicon (Si) wafer heat treatment combination jig (JIG) of the present invention can effectively prevent contamination due to the movement of the silicon wafer's mandrel, in particular, Natrum (Na) element, and provides a high quality silicon (Si) wafer. The combination jig is composed of a silicon wafer mounting jig and a support jig, and at the time of its manufacture, the required portion of the rosin in the alumina-containing annealing furnace commercially available for annealing of each jig JIG. The desired performance is exhibited by employing an industrially convenient method of performing a silicon (Si) band as a furnace (FURNACE).

Description

JIG for silicon wafer heat treatment and its manufacturing method

Figure 1 is a perspective view of a cassette boat (CASSETTE BOAT) in the cassette mother boat (CASSETTE MOTHER BOAT) type horizontal combination jig (JIG) according to the present invention.

Figure 2 is a perspective view of the mother boat (MOTHER BOAT) in the cassette mother boat (lateral type jig) jig (CASSETTE MOTHER BOAT) type.

3 is a cross-sectional view of a cassette mother boat-type horizontal combination jig (JIG) according to the present invention.

4 is a cross-sectional view taken along line A-A 'when a cassette mother boat-type horizontal combination jig (JIG) according to the present invention is brought into a furnace pipe (TUBE).

Figure 5 is a schematic cross-sectional view of a vertical combination jig for heat treatment of silicon (SILLCON) wafer in accordance with the present invention.

6 is a schematic cross-sectional view of the AN ANNEALING FURNACE according to the present invention.

* Explanation of symbols for main parts of the drawings

1: JIG for wafer placement 2: Silicon wafer

3: wafer (wafer) 4: connection pin (pin)

5: JIG 6: Silicon Plate

7: Inner Tube of Furnace 8: Liner Tube

9: vertical furnace (FURNACE)

10: ALUMINUM BOT furnace (FURNACE) bottom plate

11: Quartz glass block (BLOCK) 12: Silicon (SILICON)

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combination jig (JIG) for silicon (Si) wafer (WAFER) heat treatment used in a heat treatment process of a silicon wafer (WAFER), a manufacturing method thereof, and an annealing furnace.

Conventionally, quartz glass has been used as a jig for heat treatment of a silicon (Si) wafer (WAFER) because of its higher purity than other materials of refractory materials and the possibility of fusion by welding. A silicon wafer is placed on the quartz glass jig of high purity and placed in an electric furnace, and then heated to a high temperature of about 1000 ° C. to heat-treat the silicon wafer WAFER. Horizontal electric furnaces for vertically supporting WAFER and heat treatment, and vertical electric furnaces for performing heat treatment by horizontally holding a silicon wafer (WAFER) are used.

In recent years, however, the density of materials to be manufactured has been increased, and materials such as flash memory have been developed to avoid extreme impurities, and thus, using a high-purity quartz glass jig (JIG), only wafers ( The purity of WAFER) could not be maintained.

Therefore, in order to manufacture a higher-purity jig, a superior refining technology of raw material quartz has been developed, or a technique of manufacturing high-purity synthetic quartz glass in high-purity chemical industry has been developed. Particularly, in synthetic quartz glass, high purity quartz glass can be industrially produced at a level in which the total amount of metallic impurities does not exceed 0.1 PPM, and in order to impart heat resistance to this, in order to impart heat resistance, a target additive of several PPM is mixed with other impurities. It is also possible to implant (INPLAT) without, for example, adding 1 PPM of aluminum (Al) element.

However, even if the JIG is manufactured using such a high purity quartz glass and the heat treatment of the silicon wafer WAFER is performed in an atmosphere of high purity, contamination by alkali (ALKALI) elements, in particular sodium (Na) element is prevented. It was difficult to avoid and could not overcome the shortcoming of wasting high quality materials.

Therefore, in consideration of the above phenomenon, the present inventors have conducted an in-depth study on the cause of the silicon wafer (WAFER) contamination. As a result, the contamination by sodium (Na) element in the wafer is not caused by the direct contact of the atmosphere gas (GAS). It was found that this is due to contamination of the wafer mounting jig (JIG). It was also confirmed that the contamination of the mounting jig (JIG) was not only generated during the period during which the heat treatment process of the silicon wafer (WAFER) was carried out, but also started in the process of annealing during the quartz glass work.

As for the contamination mechanism (MECHANSIM), when the sodium (Na) pollutant such as the heat insulator of the heat treatment furnace and the wafer (WAFER) form a direct contact path through the quartz glass jig (JIG), the wafer is caused by the sodium (Na) element. Was found to cause contamination.

Therefore, when the silicon (Si) member is interposed in the path of contamination, the contamination is blocked at this point, and the quartz glass jig of the upper part (wafer side) maintains high purity at this point. The present invention has been completed by knowing that an advanced semiconductor device can be obtained without waste in a silicon wafer (WAFER) loaded on the wafer.

An object of the present invention is to provide a combination jig for heat treatment of a silicon wafer (WAFER) without contamination of the silicon wafer (WAFER).

An object of the present invention is to provide a combination jig for manufacturing a flash memory.

An object of the present invention is to provide a manufacturing method capable of manufacturing a combination jig for heat treatment of silicon (Si) wafer.

And an object of the present invention is to provide an annealing FURNACE for manufacturing a combination jig (JIG) for silicon wafer (WAFER) heat treatment.

The present invention for achieving the above object is a combination wafer (JIG) for heat treatment of silicon wafer (WAFER) consisting of a silicon wafer (WAFER) mounting jig (JIG) and a support jig (JIG) for supporting the jig (JIG). The silicon wafer WAIG mounting jig JIG and the supporting jig JIG are formed of quartz glass, and the jig JIG is connected to each other without contact with each other. A combination jig for heat treatment of a silicon wafer JIG, which is configured to be combined, and a manufacturing method thereof, and an annealing furnace for carrying out the manufacturing method.

The present invention is a combination jig (JIG) is a silicon that prevents contact of both quartz glass jig (JIG) between the support jig (JIG) formed of quartz glass, such as a wiper (JIG) for mounting a quartz glass. JIG combined as a member.

In the case of horizontal heat treatment, the wafer mounting jig (JIG) consists of a cassette boat (CASSSET BOAT) and the support jig (MOTHER BOAT).

In the case of vertical heat treatment, the supporting jig of the present invention may be regarded as a support jig of the present invention, and a lower cover which prevents the loss of thermal energy (ENERGY) from below the heat treatment furnace. . The mounting jig JIG is formed with a recessed groove or a protrusion for arranging the wafer WAFER. A plurality of silicon waiters WAFER are placed on the wafer JIG for mounting, and a silicon member is placed in the support jig and brought into an inner tube of an electric furnace and heated to a high temperature around 1000 ° C. Treatment such as oxidation treatment is performed.

According to the research of the present inventors, lithium (Li) element is usually released from all quartz glass jig (JIG) such as inner tube or wafer boat (BOAT) installed in the heating furnace, while potassium (K) and sodium ( Na) element is absorbed. Since the absorption rate of the potassium (K) element in the absorbed element is 1/10 or less of the absorption rate of the sodium (Na) element, and is gentle, it is considered that it does not move substantially. The sodium (Na) element has a high absorption rate and, moreover, a fast movement speed in quartz glass, which contaminates a silicon (Si) wafer and causes a decrease in its quality. The contamination path of this sodium (Na) element is along the surface of the solid or in the solid directly contacting the silicon gas, but not directly from the atmosphere gas (GAS) surrounding the silicon wafer.

For example, in horizontal furnaces, it has been found that the mainstream is a direct contact path such as an electric furnace, a liner tube, a quartz glass inner tube, and a quartz glass boat (BOAT) silicon wafer. In addition, if the wafer mounting jig is significantly contaminated as a sodium element, it may cause harm such as contaminating HYDROFLUORIC ACID of the jig cleaning tank or deteriorating the transparency of the quartz glass. The problem to be solved by the present invention is to process a wafer (WAFER);

The movement of the sodium (Na) element can be blocked by interposing a silicon (Si) member in the middle of the contamination path. Since the interruption point is preferably close to the wafer, the silicon (Si) member is provided in the contact portion between the wafer wafer mounting jig JIG and the supporting jig JIG. The thickness of the silicon (Si) member is good in the range of blocking the movement of alkali (ALKALI) elements, and is not particularly limited, but may be about 3 to 10 mm because of its mechanical strength and easy handling.

In the supporting jig constituting the combination jig of the present invention, quartz glass has an aluminum (Al) element content of 5 to 20 PPM, and a lithium (Li) element content of 0.1 PPM or less, and the content of sodium (Na) element is Quartz glass of the low alkali (ALKALI) type comprised below 0.1 PPM is preferable. By using the above-mentioned quartz glass, sodium (Na) element is captured just in front of the break point (the opposite side of the wafer), and the contamination of the silicon wafer can be prevented, and the aluminum in the quartz glass of the supporting jig (JIG) can be prevented. When the content of the (Al) element is less than or equal to the above range, the collection force of the sodium (Na) element is poor, and when more than or equal to the above range, the transparency of quartz glass tends to be inferior.

If the sodium (Na) element content is above the above range, the sodium (Na) element becomes saturated in the quartz glass and thus cannot be collected. According to the experiments of the present inventors, when heated in an annealing furnace at 1000 ° C. for 1000 hours, the saturation point is approached, but an increase in sodium (Na) element can be reliably observed by high sensitivity analysis even with an annealing for about 1 hour.

If the content of the lithium (Li) element is greater than or equal to the above range, contamination in the furnace due to release of the lithium (Li) element occurs, which is not preferable.

Further, the wafer-mounting jig JIG constituting the quartz glass jig JIG of the present invention is formed using various high purity quartz glass having an iron (Fe) element of 0.2 ppm or less. If the iron (Fe) element exceeds the above range, it is bad because the carrier life in the wafer in contact with it is weakened. Note that the wafer mounting jig is not contaminated with sodium (Na) element, and does not necessarily mean that the wafer is not contaminated with sodium (Na) element. In the wafer mounting jig JIG, it is necessary to block the contamination path as a silicon member on the opposite side to the wafer.

In the absence of this silicon member, a large amount of sodium (Na) element contaminates the wafer while passing through the wafer mounting jig (JIG), and the content of sodium (Na) element in the quartz glass of the jig is almost Many examples can be observed that do not increase.

An example of the manufacturing method of a combination jig | tool (JIG) is demonstrated next.

That is, the cassette boat (CASSETTE BOAT) which is a jig | tool for silicon wafer placement is produced by glassworking using various high purity quartz glass whose iron (Fe) element is 0.2PPM or less. In addition, the mother is a supporting jig using a low alkali (ALKALI) quartz glass having an aluminum (Al) element content of 0.1 PPM or less, a lithium (Li) element content of 0.1 PPM or less, and a sodium (Na) element content of 0.1 PPM. MOTHER BOAT is made of glasswork. On these jigs, wafers and insertion holes are provided by mechanical operation as necessary.

In the glass working, heat deformation remains in the quartz glass by a burner process, and thus an annealing treatment is required for removal thereof. The annealing treatment is performed by placing a jig in the annealing furnace, but as an annealing furnace, a quartz glass block (BLOCK) is placed on the top of an aluminum boat (ALUMINIUM BOAT), and a furnace with a silicon band is used.

As the jig is loaded on the silicon substrate and subjected to the annealing treatment, there is no contamination of the wafer repositioning jig due to sodium (Na) element, and the sodium of the supporting jig ( Na) can maintain the collecting power.

It is not necessary to cover the entire surface of the furnace as silicon (Si), and the size is such that the annealing quartz glass jig does not touch the road. Sufficient effect is provided by providing one silicon (Si) band at each contact point.

In the quartz glass jig (JIG) of the present invention, it is preferable that the interruption point of the sodium (Na) contamination path is close to the wafer (WAFER), so that the supporting jig (JIG) is at least 30% by weight of the total jig (JIG) weight.

As described above, the combination jig of the present invention can be processed without contaminating the object to be processed, and therefore, it is suitably used for the process of striking a thin film on silicon (Si) and wafers. It can also be used as a jig. Moreover, the annealing furnace used for manufacture of the combination jig of this invention can be applied also to manufacture of the general quartz glass product which is reluctant to contamination of an alkali (ALKALI) element.

EXAMPLE

1-5, the specific example of the combination jig for heat treatment of the silicon wafer WAFER of this invention is shown. 1-4 is a cassette mother boat horizontal jig for jig (JIG) type | mold, and FIG. 4 shows sectional drawing cut by A-A 'when it carries in into a furnace inner tube. 6 shows an annealing furnace for manufacturing a silicon wafer WAFER heat treatment combination jig JIG for releasing each jig constituting a silicon wafer WAFER heat treatment jig.

Example 1

(Manufacturing Method of JIG for Silicon Wafer Heat Treatment)

Quartz glass materials of NO. 1, NO. 2, and NO. 3 shown in Table 2 were prepared by electro welding using glass obtained by vitrifying the crystals of Samples A, B, and C in Table 1. NO. 4 is produced by the acid hydrogen chloride method (AN ACID-HYDROGEN FLAME PROCESS) from the modified powder of Sample A.

Using the quartz glass round bar as a material, a mounting jig (JIG) and a supporting jig (JIG) of a silicon (Si) wafer were fabricated by glass working, and an annealing treatment was performed to prevent thermal deformation.

The annealing treatment is performed by using a furnace in which a 25 mm quartz glass block (BL0CK) 11 is laid on the alumina annealing top plate 11 shown in FIG. 6, and a 5 mm silicon (SILICON) stand 12 is placed thereon. The annealing treatment method (the present invention method) and the treatment method (conventional method) using a furnace (FURNACE) in which the silicon zone 12 was not arranged were performed.

Table 2 shows the results of chemical analysis of the jig (JIG) subjected to the heat treatment until the heat deformation was obtained.

As shown in Table 2, the jig treated by the annealing heat treatment method according to the present invention, in which the direct annealing furnace and the quartz glass jig are not in contact with each other, maintains the purity of the material and is high purity.

On the other hand, the jig treated by the conventional method was markedly increased in alkali (ALKALI) elements, especially sodium (Na) elements, and could not be used as a wafer mounting jig (JIG).

(Examples of Wafer Heat Treatment)

In FIG. 1, the silicon wafer 2 is inserted into the wafer insertion hole 3 of the Cassette Boat 1, and the silicon plate 6 is connected as shown in FIG. Inside the furnace with a liner tube 8 and a furnace inner tube 7 shown in FIG. 4 after mounting on a mother boat 5 connected by a pin 4. It was carried in the tube 7 and the oxidation process of the wafer 2 was performed. An oxide film of good quality is formed on the obtained silicon wafer. The total weight of the CASSETTE BOAT and the weight of the MOTHER BOAT were about the same.

Example 2

Using the round bar of Example 1, the silicon wafer mounting jig (JIG) 1 and the supporting jig (JIG) 5 and the like were connected through the silicon flakes 6 as shown in FIG. It was carried in the electric furnace 9 shown in FIG. 5, and the annealing process was performed like Example 1. FIG.

As a result, the silicon wafer placing jig (JIG) 1 had no contamination of sodium (Na) element. The weight of the silicon wafer placing jig 1 was about half the weight of the supporting jig.

According to the present invention, a silicon (Si) wafer heat treatment combination jig (JIG) can effectively prevent contamination of a silicon wafer, especially contamination due to movement of sodium (Na) elements, and provide a high quality silicon (Si) wafer.

The combination jig is composed of a silicon wafer mounting jig and a support jig, and at the time of its manufacture, the required portion of the furnace on the degree of annealing in which alumina is embedded is commercially available for annealing of each jig. The desired performance is exhibited by employing an industrially convenient method of performing a silicon (Si) band as a furnace (FURNACE).

Claims (4)

In the combination jig for heat treatment of a silicon wafer consisting of a mounting jig (JIG) on which a silicon (Si) wafer is arranged and a supporting jig (JIG) for supporting the jig (JIG), the silicon wafer mounting jig ( JIG and the support jig (JIG) is formed of quartz glass, the jig for heat treatment silicon wafer (JIG), characterized in that the jig is configured to be combined through a silicon (Si) member without contacting each other. According to claim 1, wherein the quartz glass constituting the silicon wafer (WAFER) mounting jig (JIG) is a quartz glass of iron (Fe) element content of 0.2PPM or less, quartz glass constituting the support jig (HIG) Aluminum (Al) element content 5-20 PPM JIG for heat treatment of silicon (Si) wafers, characterized by quartz glass having a lithium element content of 0.1 PPM or less and sodium element content of 0.1 PPM or less . A silicon wafer (WAFER) mounting jig (JIG) is formed of quartz glass having an iron (Fe) element content of 0.2 PPM or less, while an aluminum (Al) element content is 5 to 20 PPM and a lithium (Li) element content is 0.1 PPM. Hereinafter, a method for producing a combination jig for silicon (Si) wafer (WAFER) heat treatment, in which a supporting jig (JIG) is manufactured by glass working with quartz glass having an elemental content of sodium (Ne) of 0.1 PPM or less, followed by annealing. The method of manufacturing a combination jig for heat treatment of silicon wafer (JIG) according to claim 1, wherein the annealing is performed on a silicon band. In the furnace for annealing treatment used in the manufacture of a combination jig consisting of a silicon wafer mounting jig and a support jig, the silicon jig is disposed on the required portion of the furnace so that the combination jig and the inner surface of the furnace do not come into contact with each other. An annealing furnace for the manufacture of a combination jig for heat treatment of silicon (Si) wafer.