CN114517292A

CN114517292A - Wafer tray structure and equipment

Info

Publication number: CN114517292A
Application number: CN202011299798.6A
Authority: CN
Inventors: 将镇宪; 白国斌; 高建峰; 王桂磊; 丁云凌; 田光辉
Original assignee: Institute of Microelectronics of CAS; Zhenxin Beijing Semiconductor Co Ltd
Current assignee: Institute of Microelectronics of CAS; Zhenxin Beijing Semiconductor Co Ltd
Priority date: 2020-11-18
Filing date: 2020-11-18
Publication date: 2022-05-20

Abstract

The embodiment of the invention discloses a wafer tray structure and equipment, wherein the wafer tray structure comprises: the tray wall is of an annular structure, and the annular structure is arranged at the edge of the tray bottom and can limit the wafer; wherein, the annular structure is provided with arc-shaped bulges in a surrounding way; when the wafer is placed at the bottom of the tray, the height of the arc-shaped bulge is larger than or equal to the edge height of the wafer, so that the ion reflection at the edge of the wafer can be prevented in the CVD process, the ion concentration is effectively reduced, and the ion concentration uniformity of the edge part and the central part of the wafer is ensured.

Description

Wafer tray structure and equipment

Technical Field

The invention relates to the technical field of semiconductor materials, in particular to a wafer tray structure and equipment.

Background

During the CVD (Chemical vapor Deposition) process, a tray structure is employed. The plasma density at the edge and center of the wafer can be different and it is difficult to grow the wafer uniformly by using the current tray structure in the prior art to perform the CVD process.

Therefore, the wafer tray in the prior art cannot ensure the uniformity of the ion concentration at the center and the edge of the wafer in the CVD process.

Disclosure of Invention

In view of the above, an object of the embodiments of the present invention is to provide a wafer tray structure and a method for performing a CVD process on a wafer, which effectively reduce ion concentration and ensure uniformity of ion concentration at an edge portion and a central portion of the wafer.

In a first aspect, the present application provides the following technical solutions through an embodiment:

a wafer tray structure comprising: the tray comprises a tray bottom and an annular structure, wherein the annular structure is arranged at the edge of the tray bottom; the annular structure is provided with arc-shaped bulges in a surrounding way; when a wafer is placed at the bottom of the tray, the height of the tip of the arc-shaped bulge is larger than or equal to the minimum edge height of the wafer.

Optionally, the height of the tip of the arc-shaped protrusion is half of the height of the wafer.

Optionally, the arc-shaped protrusion is connected with the edge of the wafer.

Optionally, the arc-shaped protrusion is detachably connected with the bottom of the tray.

Optionally, the tray further comprises a connecting piece, and the arc-shaped protrusion is connected with the bottom of the tray through the connecting piece.

Optionally, a distance between a tip of the arc-shaped protrusion and a plane on which the wafer is placed at the bottom of the tray is less than or equal to 10 mm.

Optionally, the distance from the tip of the arc-shaped protrusion to the annular structure is 3mm-50 mm.

Optionally, an inclined surface is arranged at the edge position of the tray bottom.

Optionally, the cross section of the arc-shaped protrusion is elliptical.

In a second aspect, based on the same inventive concept, the present application provides the following technical solutions through an embodiment:

an apparatus for performing a deposition process on a wafer, comprising: the wafer tray structure of any of claims 1-9.

One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

the wafer tray structure and the equipment provided by the embodiment, wherein the wafer tray structure comprises: the tray comprises a tray bottom and an annular structure, wherein the annular structure is arranged at the edge of the tray bottom and can limit a wafer; because the annular structure is provided with the arc-shaped bulge in a surrounding way; when the wafer is placed at the bottom of the tray, the height of the arc-shaped bulge is larger than or equal to the edge height of the wafer, so that the ion reflection at the edge of the wafer can be prevented in the CVD process, the ion concentration is effectively reduced, and the ion concentration uniformity of the edge part and the central part of the wafer is ensured.

In order to make the aforementioned and other objects, features and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

Fig. 1 is a schematic structural diagram of a first implementation manner of a wafer tray structure provided in a first embodiment of the present invention;

FIG. 2 is a schematic diagram of a ring structure of a wafer tray structure according to a first embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a second implementation manner of a wafer tray structure provided in the first embodiment of the present invention;

fig. 4 is a schematic structural diagram of a third implementation manner of a wafer tray structure provided in the first embodiment of the present invention;

fig. 5 is a schematic structural diagram of a wafer tray structure in the prior art.

Icon: 100-wafer tray structure; 200-wafer tray structure; 300-wafer tray structure; 11-the bottom of the tray; 111-inclined plane; 112-a support block; 12-a cyclic structure; 121-a connector; 13-arc-shaped bulge; 20-a wafer; 300-wafer tray structure; 31-the bottom of the tray; a 32-cyclic structure; 600-wafer tray structure.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be obtained by a person skilled in the art without inventive step based on the embodiments of the present invention, are within the scope of protection of the present invention.

First embodiment

Referring to fig. 1, a wafer tray structure 100 provided in this embodiment includes: a tray bottom 11 and a ring structure 12.

The tray bottom 11 is used for carrying the wafer 20, and a supporting block 112 for supporting the wafer 20 may be disposed at the bottom of the tray, so as to facilitate the taking and placing installation of the wafer 20. The inclined plane 111 is arranged at the edge position of the tray bottom 11, and after the wafer 20 is placed on the tray bottom 11, the space between the wafer 20 and the annular structure 12 can be reduced through the matching of the inclined plane 111 and the supporting block 112, so that the ion reflection accumulation at the edge position of the wafer 20 in the CVD process is avoided. The inclined surface 111 may be an annular flat surface, or may be a surface having a radian, without limitation.

And the ring structure 12 is used for limiting the wafer 20. The annular structure 12 is arranged at the edge of the tray bottom 11, namely surrounds the edge position of the tray bottom 11; heating of the wafer 20 is achieved through the tray bottom 11. The annular structure 12 is surrounded by an arc-shaped protrusion 13, as shown in fig. 2. When the wafer 20 is placed on the tray bottom 11, the height of the arc-shaped protrusion 13 can be within the height range of the edge of the wafer 20, and at this time, the position of the tip of the arc-shaped protrusion 13 corresponds to the height range of the thickness of the wafer 20. The height of the tip of the arc-shaped protrusion 13 may also be greater than the maximum edge height of the wafer 20, as shown in the wafer tray structure 200 of fig. 3. That is, the height of the tip of the arc-shaped protrusion 13 in the embodiment is greater than or equal to the minimum edge height of the wafer 20, specifically, the height of the tip of the arc-shaped protrusion 13 is greater than or equal to the minimum edge height of the wafer 20; wherein the minimum edge height is the height of the lower surface of the wafer 20, and the maximum edge height is the height of the upper surface of the wafer 20. Since the arc-shaped protrusion 13 is provided at a position greater than or equal to the minimum edge height of the wafer 20, the plasma density at the edge portion on the wafer 20 during the CVD process is reduced and more uniform, so that the concentration of ions grown at the center position and the edge position on the wafer 20 is more uniform.

In a preferred implementation, however, the height of the tips of the arcuate projections 13 should be within the height range of the thickness of the wafer 20. Avoid the problems of collision during the rotation or placement of the wafer 20, or failure to achieve a better ion uniformity.

The tip of the arc-shaped protrusion 13 is located at one-half height of the wafer 20, that is, the smallest circle on the arc-shaped protrusion 13 is located at one-half height of the wafer 20. The section of the arc-shaped bulge 13 can be a part of a circle or an ellipse, or other arc shapes; the smallest circle can be understood as the circle formed by the point where the arc-shaped protrusion 13 is closest to the axis of the tray bottom 11. The preferred elliptical arc with the long radius direction is an elliptical arc, so that the ion reflection at the edge position of the wafer 20 in the CVD process can be reduced to a greater extent, the ion concentration is reduced, and the accumulation is avoided.

The arcuate projections 13 may be embodied on the inner edge of the ring structure 12 at intermediate positions, such as the wafer tray structure 300 shown in fig. 4. Preferably, it is disposed at the inner edge of the top of the ring structure 12, which can improve the uniformity of ion concentration and is easy to clean.

Further, the arc-shaped protrusion 13 and the wafer 20 may be configured in a matching manner, so that the arc-shaped protrusion 13 is connected to the edge of the wafer 20 after being placed. The generation of a gap between the wafer 20 and the ring structure 12 is avoided, and the uniformity of ions on the wafer 20 near the ring structure 12 after the electric field is applied can be further improved after the gap is eliminated. The term "abutting" in this embodiment is understood to mean either a right-to-touch, or an overlap in the plane of the wafer 20, or a position of the arcuate projections 13 as close to the edge of the wafer 20 as possible so that the gap therebetween is substantially negligible.

In the two embodiments, the distance from the tip of the arc-shaped protrusion 13 to the annular structure 12 is less than or equal to 50mm, and preferably may be 3mm to 50mm, which can achieve a better effect of reducing the ion concentration. Different sizes of wafers 20 may be accommodated by providing different lengths. Meanwhile, a detachable structure may be provided between the arc protrusion 13 and the annular structure 12, and the specification of the arc protrusion 13 may be switched by the detachable structure.

Further, the distance between the tip of the arc-shaped protrusion 13 and the plane of the tray bottom 11 on which the wafer 20 is placed is 10mm or less. In order to realize that the distance of the plane for placing the wafer 20 on the tray bottom 11 is adjustable; in this embodiment, a connecting member 121 may be provided, by means of which connecting member 121 the ring-shaped structure 12 is removably or telescopically connected to the edge of the bottom 11 of the tray. The connecting member 121 can be a rod body with an adjustable length, the height of the arc-shaped protrusion 13 can be adjusted through the length adjustment of the connecting member 121 to adapt to wafers 20 with different thickness requirements, and fine adjustment control can be realized on the uniformity of ion concentration at the edge of the wafer 20 through the height adjustment.

In addition, in the present embodiment, the inclined surface 111 is disposed on the tray bottom 11 to prevent the wafer 20 from sliding to the edge when the wafer is placed on the tray bottom 11. Meanwhile, the ring structure 12 is configured to be height-adjustable or detachable, which not only ensures the ion concentration on the edge of the wafer 20 to be more uniform, but also facilitates the cleaning of the wafer tray structure 100 in this embodiment.

It should be noted that, as shown in fig. 5, in the wafer tray structure 600 in the prior art, after the wafer 20 is placed on the tray bottom 31, a large gap exists between the wafer 20 and the annular structure 32, and meanwhile, since the annular structure 32 is a vertical wall structure, the increase of the ion concentration cannot be effectively suppressed, the cleaning work of the tray bottom 32 is not facilitated, and the suppression of the ion concentration by the wafer tray structure 300 in the present application cannot be realized.

It should be further noted that the CVD process in this embodiment includes, but is not limited to: LPCVD (Low-Pressure Chemical Vapor Deposition), APCVD (atmospheric-Pressure Chemical Vapor Deposition), SACVD (sub-atmospheric Chemical Vapor Deposition), UHCVD (ultra-high-vacuum Chemical Vapor Deposition), PECVD (Plasma Enhanced Chemical Vapor Deposition), and RTCVD (rapid thermal Chemical Vapor Deposition), among others.

The present embodiment provides a wafer tray structure 100, which includes: the wafer positioning device comprises a tray bottom 11 and an annular structure 12, wherein the annular structure 12 is arranged at the edge of the tray bottom 11 and can limit a wafer 20; wherein, an arc-shaped bulge 13 is arranged on the annular structure 12 in a surrounding manner; when the wafer 20 is placed on the bottom 11 of the tray, the height of the arc-shaped protrusion 13 is greater than or equal to the edge height of the wafer 20, so that the ion reflection at the edge of the wafer 20 can be prevented in the CVD process, the ion concentration is effectively reduced, and the ion concentration uniformity of the edge part and the central part of the wafer 20 is ensured.

Second embodiment

Referring to fig. 3, based on the same inventive concept, an apparatus for performing a deposition process on a wafer according to the present embodiment includes: a wafer pallet structure as claimed in any one of the first embodiments.

The wafer tray structure used in the apparatus for performing a deposition process on a wafer in this embodiment may refer to the corresponding description in the first embodiment, and is not described in detail in this embodiment.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "upper", "lower", "horizontal", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings or orientations or positional relationships that the products of the present invention conventionally place when used, and are only used for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the devices or elements referred to must have specific orientations, be constructed in specific orientations, and be operated, and thus, should not be construed as limiting the present invention. In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed," "mounted," and "connected" are to be construed broadly, e.g., as meaning fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Claims

1. A wafer tray structure, comprising: the tray comprises a tray bottom and an annular structure, wherein the annular structure is arranged at the edge of the tray bottom;

the annular structure is provided with arc-shaped bulges in a surrounding way; when a wafer is placed at the bottom of the tray, the height of the tip of the arc-shaped bulge is larger than or equal to the minimum edge height of the wafer.

2. The wafer tray structure of claim 1, wherein the height of the tips of the arcuate projections is at one-half the height of the wafer.

3. The wafer tray structure of claim 1, wherein the arcuate projections meet an edge of the wafer.

4. The wafer tray structure of claim 1, wherein the arcuate projection is removably attached to the tray bottom.

5. The wafer tray structure of claim 4, further comprising a connector through which the arcuate projections connect with the tray bottom.

6. The wafer tray structure of claim 4, wherein the distance between the tip of the arc-shaped protrusion and the plane of the bottom of the tray on which the wafer is placed is less than or equal to 10 mm.

7. The wafer tray structure of claim 1, wherein the distance from the tip of the arc-shaped protrusion to the ring-shaped structure is 3mm to 50 mm.

8. The wafer tray structure of claim 1, wherein the edge position of the tray bottom is provided with a bevel.

9. The wafer tray structure of claim 1, wherein the arcuate projections are elliptical in cross-section.

10. An apparatus for performing a deposition process on a wafer, comprising: the wafer tray structure of any of claims 1-9.