CN111235549A

CN111235549A - Wafer film growth method, furnace tube wafer arrangement system and baffle

Info

Publication number: CN111235549A
Application number: CN202010045542.6A
Authority: CN
Inventors: 潘玉妹; 詹冬武; 潘国卫
Original assignee: Yangtze Memory Technologies Co Ltd
Current assignee: Yangtze Memory Technologies Co Ltd
Priority date: 2020-01-16
Filing date: 2020-01-16
Publication date: 2020-06-05

Abstract

The application discloses a wafer film growth method furnace tube wafer arrangement system, which comprises: a furnace tube; the crystal boat is positioned in the furnace tube and comprises a plurality of placing grooves; the first blocking piece and the second blocking piece are respectively positioned at one end of the wafer boat; the product wafers are positioned in the wafer boat, and the surfaces of the product wafers are provided with films; the surfaces of the first separation blade and the second separation blade are provided with films of the same type as the product sheets, the plurality of product sheets are located between the first separation blade and the second separation blade, and part of the product sheets are adjacent to the first separation blade or the second separation blade. Through with the separation blade and the adjacent setting of product piece to prevent the wafer direct contact of product piece and different grade type, can effectively avoid because of the product piece thickness that the heat radiation difference caused super poor, can make the thickness of product piece more even, the uniformity is better, the promotion of very big degree when improving product piece yields product quality.

Description

Wafer film growth method, furnace tube wafer arrangement system and baffle

Technical Field

The present invention relates to semiconductor technology, and more particularly, to a method for growing a wafer film and a furnace wafer arrangement system.

Background

With the progress of science and technology, semiconductor electronic products have been applied to various fields of social life, and generally, these semiconductor electronic products have semiconductor chips, which have played an increasingly important role in the production life of today.

Semiconductor chips are usually made from wafers (Wafer) through multiple processes, in the manufacturing process of the semiconductor chips, a furnace tube is an indispensable device, and the furnace tube can be used in the processes of diffusion, oxidation, annealing and the like of the wafers, wherein, the process of forming different types of films on the wafers by using the furnace tube is the basic process of the semiconductor chips, in the process, a plurality of product pieces (wafers) are firstly placed on a crystal boat, and then the crystal boat is placed in the furnace tube.

As shown in fig. 1, in the prior art, it is common to place control wafers 200 at appropriate positions above, in the middle, and below the boat 100, and to simulate the film condition of the product wafers 300 through the control wafers 200, so as to monitor the condition of the product wafers 300 in different positions in the same equipment in the same batch. As shown in fig. 2, the film thickness deviation of the product pieces 300 of the same batch usually occurs on the topmost first product piece 301, and the specific deviation position is the middle area of the product piece 301, wherein the film thickness of the middle area is much larger than that of the peripheral area, so that the product piece cannot be used, the problem occurs at a very high frequency, and the yield of the product is greatly affected.

Disclosure of Invention

The invention aims to provide a wafer film growth method and a furnace tube wafer arrangement system, wherein two ends of a wafer boat of a furnace tube are provided with baffle plates, and the surfaces of the baffle plates are provided with films of the same type as a product sheet, so that the baffle plates have heat conduction performance similar to the product sheet, the over-difference of the film thickness of the product sheet caused by heat conduction difference can be effectively avoided, the film thickness of the middle area of the product sheet is reduced, the film thickness of the product sheet is more uniform, the consistency is better, and the yield and the performance of the product sheet are improved.

According to an aspect of the present invention, there is provided a method for growing a wafer thin film, the method comprising: placing separation blades at two ends of the wafer boat; putting the product wafer into the wafer boat; putting the wafer boat into a furnace tube for heating; introducing reaction gas into the furnace tube to enable a film with a preset thickness to grow on the surface of the product sheet; the product sheets are positioned between the baffle plates, the surfaces of the baffle plates are provided with films of the same type as the product sheets, and the growth state of the films on the surfaces of the product sheets is monitored by measuring the control sheets.

Preferably, the growth method further comprises the steps of placing a control wafer in a wafer boat, placing the control wafer and the product wafer in the wafer boat for heating in a furnace pipe at the same time, and monitoring the growth state of the thin film on the surface of the product wafer by measuring the control wafer.

Preferably, the thickness of the baffle plate is the same as the thickness of the product sheet.

Preferably, the baffle plate has the same edge profile as the product sheet.

Preferably, the material of the thin film of the baffle plate comprises at least one of silicon oxide and silicon nitride.

Preferably, the baffle plate has a film thickness of

Preferably, the baffle is reusable.

Preferably, at least two baffle plates are arranged at two ends of the wafer boat respectively; the number of the control pieces is at least two, the control pieces are respectively arranged at two ends of the wafer boat, and the control pieces are positioned on the inner side of at least one blocking piece.

Preferably, one end of the boat is provided with two blocking pieces and two control pieces, and the blocking pieces and the control pieces are alternately arranged, so that one control piece is positioned between the two blocking pieces.

According to another aspect of the present invention, a furnace wafer arrangement system is provided, which includes: a furnace tube; the crystal boat is positioned in the furnace tube and comprises a plurality of placing grooves for placing product pieces; the first blocking piece and the second blocking piece are respectively positioned at one end of the placing groove; wherein the surfaces of the first and second baffle plates have the same type of film as the product sheet.

Preferably, the plurality of placing grooves are arranged equidistantly.

Preferably, the first blocking piece and/or the second blocking piece are multiple pieces, and at least one of the first blocking pieces and at least one of the second blocking pieces are adjacent to the placement groove of the product pieces.

Preferably, the first baffle and the second baffle are both reusable.

Preferably, the wafer arrangement system further includes a control wafer, the control wafer is located in the placing groove of the boat, the number of the control wafer is at least 2, the control wafer is located at one end of the placing groove of the boat, and the control wafer is adjacent to the first blocking piece or the second blocking piece.

Preferably, the control wafer includes a first control wafer and a second control wafer, the first control wafer and the first blocking wafer are located at the same end of the boat, and the second control wafer and the second blocking wafer are located at the other end of the boat.

Preferably, the first control piece and the first blocking piece are 2 pieces, and the two pieces are alternately arranged, so that 1 piece of the first control piece is located between 2 pieces of the first blocking piece, and one side surface of 1 piece of the first blocking piece is adjacent to the placing groove of the product piece.

Preferably, the wafer arrangement system further includes a first support, and the first support is configured to move the first blocking piece and the second blocking piece, and place the first blocking piece and the second blocking piece into the boat or take the first blocking piece and the second blocking piece out of the boat.

Preferably, the wafer arraying system further comprises a second support for moving the product sheet.

According to another aspect of the invention, the baffle plate is characterized in that the surface of the baffle plate is provided with a film of the same type as a product plate, the baffle plate is used in a wafer film growth process, and the baffle plate is arranged at the end part of a wafer boat.

According to the wafer film growth method and the furnace tube wafer arrangement system provided by the embodiment of the invention, the blocking pieces are arranged at the two ends of the wafer boat, and the films of the same type as the product pieces are arranged on the surfaces of the blocking pieces, so that the heat conduction performance of the blocking pieces is similar to that of the product pieces, and the blocking pieces are arranged adjacent to the product pieces, so that the product pieces are prevented from being in direct contact with wafers of different types, the thickness of the product pieces is more uniform and better in consistency due to the difference of heat conduction (heat radiation), and the product quality is greatly improved while the yield of the product pieces is improved.

Drawings

The above and other objects, features and advantages of the present invention will become more apparent from the following description of the embodiments of the present invention with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of a wafer arrangement of a furnace tube in the prior art.

FIG. 2 shows a schematic diagram of a prior art top product plate of a boat.

Fig. 3 is a schematic diagram illustrating a method for growing a wafer film according to an embodiment of the invention.

Fig. 4 shows a schematic cross-sectional view of a baffle plate according to an embodiment of the invention.

FIG. 5 is a schematic view of a furnace wafer arrangement system according to an embodiment of the invention.

FIG. 6 is a partial enlarged view of the furnace wafer arrangement system according to the embodiment of the invention.

Detailed Description

The invention will be described in more detail below with reference to the accompanying drawings. Like elements in the various figures are denoted by like reference numerals. For purposes of clarity, the various features in the drawings are not necessarily drawn to scale. In addition, certain well known components may not be shown. For simplicity, the semiconductor structure obtained after several steps can be described in one figure.

It will be understood that when an element or region is referred to as being "on" or "over" another element or region, it can be directly on the other element or region or intervening elements or regions may also be present. Also, if the structure is turned over, that element or region may be "under" or "beneath" another element or region.

If it is intended to describe the situation as being directly above another element, another region, the expression "directly above … …" or "above and adjacent to … …" will be used herein.

In the following description, numerous specific details of the invention, such as structure, materials, dimensions, processing techniques and techniques of the devices are described in order to provide a more thorough understanding of the invention. However, as will be understood by those skilled in the art, the present invention may be practiced without these specific details.

Fig. 3 is a schematic diagram illustrating a method for growing a wafer thin film according to an embodiment of the present invention, the method comprising the steps of:

s10 placing blocking sheets at two ends of the boat;

s20 placing control plates at two ends of the boat;

s30, putting the product wafer into the wafer boat;

s40, putting the wafer boat into a furnace tube for heating;

s50, introducing reaction gas into the furnace tube, and enabling the surface of the product sheet to grow a film with a preset thickness.

Specifically, the wafer boat carries a blocking sheet, a control sheet and a product sheet, wherein the surface of the blocking sheet is provided with a film of the same type as the product sheet, so that the blocking sheet also has a heat conduction performance similar to the product sheet, and when the wafer boat is heated in a furnace tube, the temperatures of all parts of the wafer boat are more consistent, thereby avoiding poor film growth thickness uniformity and size over-tolerance of the product sheet caused by heat conduction (heat radiation) difference. Furthermore, the control wafer is arranged on the inner sides of the blocking sheets at two ends of the wafer boat, and the growth state of the surface film of the product wafer on the same wafer boat can be monitored through measurement of the control wafer.

Further, when the manufacturing process is mature and the consistency of the product pieces meets a certain requirement, the film growth state of the product pieces can be controlled by controlling the flow rate of the reaction gas introduced into the furnace tube and the reaction time, so that the step of S20 is omitted, namely, the step of placing the control pieces in the wafer boat is omitted, meanwhile, the placement grooves occupied by the control pieces are also avoided, the product pieces can be placed in the corresponding placement grooves, more products can be produced in one batch, the production efficiency is further improved, and the production cost is reduced.

Fig. 4 shows a schematic cross-sectional view of a baffle plate according to an embodiment of the present invention, wherein the baffle plate 400 comprises a substrate 410 and a film 420 disposed on a surface of the substrate 410, wherein the material of the film 420 is, for example, the same as that of the product sheet 300, and further, the thickness of the baffle plate 400 (the sum of the thickness of the substrate 410 and the thickness of the film 420) can also be the same as that of the product sheet 300, so that the baffle plate 400 has similar thermal conductivity to that of the product sheet 300. Preferably, thin films 420 are disposed on the upper and lower surfaces of the substrate 410, the thin films 420 are, for example, silicon oxide layers, silicon nitride layers or composite layers formed by alternately stacking silicon oxide and silicon nitride, and the thin films have a thickness of, for example, about

Of course, the films 420 on the upper and lower surfaces of the substrate 410 may be made of the same material or different materials, and the thicknesses thereof may be the same or different, and may be adjusted according to the conditions of the product sheet 300.

Fig. 5 is a schematic view of a furnace wafer arrangement system according to an embodiment of the invention, which includes a furnace (not shown) and a boat 100, and further, may include a first support 510 and a second support 520, the wafer boat 100 is internally provided with a plurality of placing grooves 110 for placing wafers, the wafers comprise control plates, blocking plates and product plates 300, the control plates, the blocking plates and the product plates 300 are all arranged in the wafer boat 100 through the placing grooves 110, the blocking plates comprise a first blocking plate 401 positioned at the upper end of the wafer boat 100 and a second blocking plate 402 positioned at the lower end of the wafer boat 100, similarly, the control plates also comprise a first control plate 201 positioned at the upper end of the wafer boat 100 and a second control plate 202 positioned at the lower end of the wafer boat 100, the product plates 300 are positioned between the first blocking plate 401 and the second blocking plate 402, the top surfaces of the topmost ones of the product plates 300 are adjacent to the bottom surface of the first blocking plate 401, and the bottom surfaces of the bottommost ones of the product plates 300 are adjacent to the top surface of the second blocking plate 402; because the surface of the separation blade is provided with the film with the same type as the product sheet 300, the heat conduction performance of the separation blade is similar to that of the product sheet 300, when the boat 100 is placed into a furnace tube for heating, the heat radiation performance of each wafer (including a control sheet, the separation blade and the product sheet) in the boat 100 is more consistent, the uniformity of the thickness of the product sheet close to the outer side (adjacent to the separation blade) is ensured, the product sheet is prevented from being scrapped due to the fact that the thickness of the middle area is too thick and the size is out of tolerance, the yield of the product sheet can be effectively improved, and the production cost is saved.

Furthermore, the surface film of the baffle plate can not be changed in the related manufacturing process of the furnace tube, so the baffle plate can be repeatedly used, and tests prove that the repeated use of the baffle plate can not cause the problem that the product plate generates particles. Preferably, the times of repeated use of the baffle can be specified, and the baffle is replaced when the times of use reaches a threshold value, so that the production stability is ensured while the cost is saved.

In order to facilitate the replacement of the blocking plates, the furnace tube wafer arrangement system further comprises a first support 510, the first support 510 can simultaneously clamp and move the first blocking plate 201 and the second blocking plate 202, the moving efficiency of the wafer can be improved, and the production efficiency is further improved.

Fig. 6 shows a partial enlarged view of the upper end of the boat in the furnace tube wafer arrangement system according to the embodiment of the invention, preferably, the first control wafer 201 and the first blocking plate 401 in the boat have 2 pieces, and are alternately arranged from top to bottom, so that the uppermost one of the boat is the first control wafer 201, the other one of the first control wafer 201 is located between the two first blocking plates 401, and the lower surface of the first blocking plate 401 located below is adjacent to the product wafer 300, thereby preventing the product wafer from directly contacting with wafers of different types, and preventing the thickness from being over-different due to the thermal radiation effect, and greatly improving the product quality. Similarly, the lower end of the boat may be designed similarly, and will not be described herein.

In the above description, the technical details of the boat patterning, the wafer diffusion, the oxidation, the annealing, and the like are not described in detail. Those skilled in the art will appreciate that the desired wafer arrangement system may be formed by various techniques. In addition, in order to form the same arrangement system, those skilled in the art can also design similar structures that are not exactly the same as the above-described structures, and the same should also be included in the protection scope of the present invention.

The embodiments of the present invention have been described above. However, these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. The scope of the invention is defined by the appended claims and equivalents thereof. Various alternatives and modifications can be devised by those skilled in the art without departing from the scope of the invention, and these alternatives and modifications are intended to fall within the scope of the invention.

Claims

1. A method for growing a thin film on a wafer, the method comprising:

placing separation blades at two ends of the wafer boat;

putting the product wafer into the wafer boat;

putting the wafer boat into a furnace tube for heating; and

introducing reaction gas into the furnace tube to enable a film with a preset thickness to grow on the surface of the product sheet;

wherein the product pieces are positioned between the baffle sheets, and the surface of the baffle sheets is provided with a film of the same type as the product pieces.

2. The growth method according to claim 1, further comprising placing a control wafer in a boat, heating the control wafer in a furnace tube simultaneously with the product wafer, and monitoring the growth state of the thin film on the surface of the product wafer by measuring the control wafer.

3. The growing method according to claim 1, wherein the thickness of the baffle plate is the same as the thickness of the product sheet.

4. The growing method according to claim 1, wherein the baffle plate has the same edge profile as the product plate.

5. The growth method according to claim 1, wherein the material of the thin film of the baffle plate comprises at least one of silicon oxide and silicon nitride.

6. The growing method according to claim 1, wherein the dummy wafer has a film thickness of

7. The growing method according to claim 1, wherein the baffle is reusable.

8. The growing method according to claim 2, wherein at least two said blocking plates are respectively disposed at two ends of said boat; the number of the control pieces is at least two, the control pieces are respectively arranged at two ends of the wafer boat, and the control pieces are positioned on the inner side of at least one blocking piece.

9. The growing method according to claim 2, wherein one end of the boat has two said blocking plates and two said control plates, and the blocking plates and the control plates are alternately arranged so that one of the control plates is located between two of the blocking plates.

10. A furnace wafer arrangement system, comprising:

a furnace tube;

the crystal boat is positioned in the furnace tube and comprises a plurality of placing grooves for placing product pieces; and

the first blocking piece and the second blocking piece are respectively positioned at one end of the placing groove;

wherein the surfaces of the first and second baffle plates have the same type of film as the product sheet.

11. The wafer arraying system of claim 10 wherein the plurality of placement slots are arranged equidistantly.

12. The wafer routing system of claim 10, wherein the first and/or second baffle plates are a plurality of plates, at least one of the first baffle plates and at least one of the second baffle plates being adjacent to the product plate placement slot.

13. The wafer arrangement system according to claim 10, further comprising a control wafer, wherein the control wafer is located in the placing slot of the wafer boat, the number of the control wafer is at least 2, the control wafer is located at one end of the placing slot of the wafer boat, and the control wafer is adjacent to the first blocking plate or the second blocking plate.

14. The wafer routing system of claim 13, wherein the control wafer comprises a first control wafer and a second control wafer, the first control wafer and the first blocking plate are located at the same end of the boat, and the second control wafer and the second blocking plate are located at the other end of the boat.

15. The wafer arrangement system according to claim 14, wherein the first control pieces and the first blocking pieces are 2 pieces, and the two pieces are alternately arranged, so that 1 piece of the first control pieces is located between the two first blocking pieces, and one side surface of 1 piece of the first blocking piece is adjacent to the placing groove of the product piece.

16. The baffle plate is characterized in that the surface of the baffle plate is provided with a film of the same type as a product plate, and the baffle plate is used in a wafer film growth process.