CN217239426U

CN217239426U - Wafer supporting device and semiconductor process equipment

Info

Publication number: CN217239426U
Application number: CN202123128191.4U
Authority: CN
Inventors: 张赛谦
Original assignee: Piotech Inc
Current assignee: Piotech Inc
Priority date: 2021-12-13
Filing date: 2021-12-13
Publication date: 2022-08-19
Anticipated expiration: 2031-12-13

Abstract

The utility model discloses an improve wafer strutting arrangement of edge convection, include: a support plate has a top surface and a bottom surface. The top surface of the support plate is provided with a bearing surface and a non-bearing surface, wherein the non-bearing surface is positioned on the outer side of the bearing surface, a plurality of through holes are formed between the non-bearing surface and the bottom surface, and the through holes surround the bearing surface and are used for guiding gas to the lower part of the support plate. Furthermore, the utility model also provides a semiconductor process equipment.

Description

Wafer supporting device and semiconductor process equipment

Technical Field

The present invention relates to a wafer supporting device, and more particularly to a wafer supporting device located in a semiconductor process chamber.

Background

In semiconductor manufacturing processes such as Plasma Enhanced Chemical Vapor Deposition (PECVD), atomic deposition (ALD), plasma etching, and Physical Vapor Deposition (PVD), there are strict requirements for plasma uniformity in a reaction chamber. As is well known in the art, the chambers used to perform these plasma processes contain an arrangement of upper and lower electrodes, and it is generally desirable to maximize the area of the upper and lower electrodes as much as possible to achieve a more desirable plasma uniformity. However, other configurations in the chamber (e.g., showerhead assembly and pumping assembly) can limit the size of these electrodes.

In one chamber configuration in which the pumping assembly is located on the inner wall of the chamber and surrounds the periphery of the wafer support device (e.g., pumping ring), even the pumping assembly may have sidewall flow control devices for controlling the flow of gas around the wafer support device or wafer edge, which configuration is advantageous for achieving a more symmetrical exhaust. However, a problem with this arrangement is that there is some dimensional tolerance between the sidewall flow control pumping assembly and the wafer support device with the bottom electrode, which tends to cause non-uniform and unstable gas flow, further diffraction arcing (arcing) and particle accumulation, which are physical phenomena detrimental to the process.

Chinese patent publication No. CN210325711U discloses an etching process apparatus, wherein a wafer supporting plate is loaded in a process chamber, and a grounded conductive ring is disposed between a sidewall of the supporting plate and an inner wall of the chamber for discharging electric charges dissipated from the supporting plate. The conductive ring is provided with a plurality of through holes for discharging etching gas from the upper part of the cavity to the lower part of the cavity, thereby improving the etching rate of the edge of the wafer. However, the conductive ring occupies a certain volume and surrounds the support plate, so that the space for the support plate to mount the lower electrode is limited. Furthermore, the installation of the conductive ring around the support disk is in fact complicated in its structure, so that the flow of gas and the distribution of the radio-frequency electric field inside the chamber are affected, with the risk of particle accumulation and arcing.

Therefore, it is necessary to develop a more suitable chamber configuration method for the performance of the wafer edge process.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a wafer strutting arrangement and semiconductor process equipment are used for improving edge convection.

The utility model provides a wafer strutting arrangement contains: the gas-discharging support comprises a support disc, a gas-discharging device and a gas-discharging device, wherein the support disc is provided with a top surface and a bottom surface, the top surface of the support disc is provided with a bearing surface and a non-bearing surface, the non-bearing surface is positioned on the outer side of the bearing surface, a plurality of through holes are formed between the non-bearing surface and the bottom surface, and the through holes surround the bearing surface and are used for discharging gas to the lower part of the support disc.

The wafer supporting device has the beneficial effects that: a plurality of through holes are formed between the non-bearing surface and the bottom surface, and the through holes surround the bearing surface and are used for discharging gas below the supporting disc so as to improve edge convection, facilitate generation of more uniform electric field distribution, reduce assembly of additional components, reduce tolerance of component manufacturing and installation and reduce complexity of structure and component materials. And the risk of arcing and particle contamination that is detrimental to the fabrication of thin films is also effectively reduced.

Further, the supporting disc is made of ceramic, an electrode plate is buried in the supporting disc, the electrode plate covers the bearing surface and the part of the non-bearing surface, and the distance from the electrode plate to the top surface of the supporting disc is 1 mm-3 mm.

Further, the electrode plate is a woven mesh, and the distance between the edge of the woven mesh and the support disc is 3mm to 10 mm.

Another object of the present invention is to provide a semiconductor processing apparatus, comprising: a cavity; and the wafer supporting device is arranged in the cavity, wherein a gap is formed between one side surface of the supporting plate and one inner side surface of the cavity when the supporting plate is positioned at a process position, and the gap is 1mm to 3 mm.

Drawings

The invention can be further understood with reference to the following drawings and description. Non-limiting and non-exhaustive examples are described with reference to the following figures. The components in the drawings are not necessarily to scale; emphasis instead being placed upon illustrating the structures and principles.

FIG. 1 is a schematic view of a semiconductor processing apparatus using the wafer support apparatus of the present invention.

Fig. 2A and 2B illustrate an example of the shape of the through-hole.

Detailed Description

The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which specific exemplary embodiments are shown by way of illustration. The claimed subject matter may, however, be embodied in many different forms and should not be construed as limited to any example embodiments set forth herein; the exemplary embodiments are merely illustrative. As such, the present invention is intended to provide a reasonably broad scope to claimed subject matter as claimed or as encompassed.

Words and phrases used in this specification

Reference to "in one embodiment" is not necessarily to the same embodiment, and reference to "in other embodiment(s)" as used within this specification is not necessarily to a different embodiment. It is intended that, for example, claimed subject matter include all or a portion of the exemplary embodiments in combination.

Fig. 1 shows a schematic view of a semiconductor processing apparatus, in particular a semiconductor apparatus for performing a plasma process, which mainly comprises a chamber 1 for performing a plasma process, providing an enclosure for processing a wafer. The shower assembly 2 is disposed on the top of the chamber 1 and is connected to a gas source 3 and an RF signal source 4. The showerhead assembly 2 has a gas distribution unit that supplies gas from a gas source 3 down into the chamber and an upper electrode configured to receive the rf signal and transmit rf energy down. In practice, the upper electrode may be part of the gas distribution unit.

The wafer support device 5 of the present invention is disposed at a suitable position in the chamber. The wafer support device 5 includes a support plate 51 having a top surface 52 and a bottom surface 53. Since a heating coil is usually embedded in the pan, the support plate 51 is also called a heating pan. A plurality of through holes 54 extend between the top surface 52 and the bottom surface 53 for directing gases, such as reactive gases or inert gases, supplied from the showerhead assembly 2 from above the chamber down to below the support plate 51 to an exhaust assembly (not shown). Thus, the gas supplied to the chamber is exhausted mainly through the through holes 54, not mainly from the side of the support plate 51, so that the flow rate at the wafer edge is expected to perform.

Fig. 2A and 2B respectively show an example of the shape of the through hole 54. According to the top view of the support plate 51, the top surface of the plate has a carrying surface 55 and a non-carrying surface 56, wherein the carrying surface 55 is the area covered by the wafer, and the non-carrying surface 56 is the area not covered by the wafer (for example, the wafer diameter is larger than 150 mm). It should be noted that the non-bearing surface 56 is disposed at the periphery of the bearing surface 55 and exposed to the process environment, and the circular through holes 54' or the oval through holes 54 ″ are uniformly and annularly arranged on the non-bearing surface 56 to surround the bearing surface 55. Thus, the proximity of the through holes 54', 54 "to the wafer edge determines the flow rate of the gas at the wafer edge. It should be understood that the through holes of the present invention are not limited to the pattern of the icons. For example, the extending direction of the through hole is vertically extended in fig. 1, but in other embodiments, the extending direction of the through hole may be obliquely extended with respect to a central axis (not shown) of the support plate 51. Alternatively, while the opening major axis directions of the oval shaped through holes 54 "are all directed toward the center of the disk, in other embodiments the opening major axis directions may not be directed toward the center of the disk. Alternatively, the openings at the two ends of the through hole may have different shapes, or the same shape but different directions. The diameter of the circular through hole is 0.1mm-10.0mm, and the major axis of the oval through hole is 0.1mm-10.0mm, so that the effects of limiting gas circulation, inhibiting flow rate and enabling a gas flow field to be more uniform can be achieved, and the problem that gas cannot be discharged in time due to too small size and too large flow resistance can be avoided.

The support plate 51 may be ceramic and has an embedded grounded electrode plate 57 as the lower electrode in the chamber, establishing an intra-chamber electric field with the upper electrode in the shower assembly 2. With the configuration of the through

holes

54, 54', 54 ″ provided in the wafer supporting device 51 of the present invention, the distance 58 between the electrode plate 57 and the top surface 52 of the supporting plate 51 is preferably 1mm to 3 mm. In some embodiments of the present invention, the distance 58 between the electrode plate 57 and the top surface 52 of the support disc 51 is 1 mm. In some embodiments of the present invention, the distance 58 between the electrode plate 57 and the top surface 52 of the support disc 51 is 3 mm. Within the range of the distance, the transmission of radio frequency current can be ensured, otherwise, too large or too small distance is not beneficial to processing, sintering and molding.

In one embodiment, the electrode plate 57 is a woven mesh electrode, and the distance between the edge of the woven mesh electrode and the supporting plate 51 is preferably 3mm to 10 mm. In some embodiments of the present invention, the distance between the edge of the support plate 51 and the support plate is 3 mm. In some embodiments of the present invention, the distance between the edge and the support plate 51 is 10 mm.

In addition, when the wafer support device 5 is installed in the chamber 1, the size of the support plate 51 is properly selected to have a gap between the side surface of the support plate 51 and an inner side surface of the chamber 1. As shown in the enlarged view of fig. 1, a gap G, preferably ranging from 1mm to 3mm, is formed between the side of the support plate 51 in the processing position and the inner side surface of a liner 6 of the chamber 1. In some embodiments of the invention, the gap is 3mm apart. In some embodiments of the invention, the gap is 10mm apart. The reason for this gap G is to avoid particle contamination of the side of the support disk 51 after mounting, due to the tolerances of the wafer support device 5 during the process. The gap G is controlled to ensure that the gas flow is still primarily through the lower row of vias 54 without affecting the wafer edge deposition rate performance.

The outer side of the supporting plate 51 may be provided with other structures, such as a structure extending downward on the outer side of the plate body as shown in fig. 1, but the present invention is not limited thereto. It will be appreciated that structural differences outside the disk will also have a substantial effect on gas flow, as the disk outside structure will determine the size of the gap G. In some embodiments, the desired airflow performance may be achieved by mounting the support plate 51 on its side or by performing a sintering process on the surface of the plate itself. Alternatively, the desired airflow performance may be achieved by modifying the configuration of the inner sidewall or liner of the chamber 1 to match the side of the support plate 51.

Claims

1. A wafer support apparatus comprising: a supporting disk, has a top surface and a bottom surface, its characterized in that: the top surface of the supporting disc is provided with a bearing surface and a non-bearing surface, wherein the non-bearing surface is positioned on the outer side of the bearing surface, a plurality of through holes are formed between the non-bearing surface and the bottom surface, and the through holes surround the bearing surface and are used for guiding gas to the lower part of the supporting disc.

2. The apparatus of claim 1, wherein the support plate is ceramic and has an electrode plate embedded therein, the electrode plate covering the carrying surface.

3. The wafer support apparatus of claim 2, wherein the electrode plate covers portions of the carrying surface and the non-carrying surface.

4. The wafer support apparatus of claim 2 or 3, wherein the distance from the electrode plate to the top surface of the support plate is 1mm to 3 mm.

5. The wafer support apparatus of claim 2 or 3, wherein the electrode plate is a woven mesh, and the edge of the woven mesh is 3mm to 10mm away from the support plate.

6. The wafer support apparatus of claim 1, wherein the through-hole is circular in cross-section.

7. The wafer support apparatus of claim 6, wherein the through hole has a diameter dimension of 0.1mm to 10.0 mm.

8. The wafer support apparatus of claim 1, wherein the through-hole is oval in cross-section.

9. The wafer support apparatus of claim 8, wherein the through-hole has a major axis dimension of 0.1mm to 10.0 mm.

10. A semiconductor processing apparatus, comprising: a cavity; and the wafer support apparatus of any of claims 1 to 9 mounted in the chamber, wherein: when the supporting disc is located at a process position, a gap is formed between one side face of the supporting disc and one inner side face of the cavity, and the gap is 1mm to 3 mm.