KR20050002073A - Semiconductor manufacturing apparatus with improved control of process parameter - Google Patents

Abstract

PURPOSE: A semiconductor manufacturing apparatus is provided to control effectively process parameter by forming curvature at backside of a wafer for increasing the contact area between the wafer and a support. CONSTITUTION: A semiconductor manufacturing apparatus is provided with a support(200) for loading a wafer(100). In order to increase the contact area between the wafer and the support, a curvature is formed at a backside(102) of the wafer. Also, the support has a curvature(201) corresponding to the curvature of the backside of the wafer. Heat or power is applied to the wafer via the support.

Description

Semiconductor manufacturing equipment that can efficiently control process variables {SEMICONDUCTOR MANUFACTURING APPARATUS WITH IMPROVED CONTROL OF PROCESS PARAMETER}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device, and more particularly, to a semiconductor manufacturing apparatus capable of adjusting semiconductor process parameters due to bending by having a support having a curvature corresponding to a back side of a wafer having a curvature at its rear surface. It is about.

The manufacturing process of a semiconductor device is a series of processes for forming a pattern on a substrate according to a design rule. One of the most important in this process is the proper control of process parameters such as temperature, pressure or power.

Of the process variables, the temperature of the chuck that controls the temperature of the front side of the wafer on which the reaction occurs depends on the requirements of the process application and the limitations of the hardware. At this time, if different temperatures of the cathode (Cathode) are used in the same chamber as the other processes proceed together, it is disadvantageous from the viewpoint of TAT, which directly affects the yield. In addition, changing the temperature of the cathode can have a significant impact on the lifetime of the equipment and the stability of each process.

On the other hand, in almost all semiconductor device manufacturing processes up to now, these process parameters are controlled only at the temperature of the chuck on which the wafer is raised and at the front of the wafer where the reaction takes place. As a result, higher integration reduces margins in the manufacturing process itself and also limits the control of process variables.

Therefore, there is a need for a method for more effectively controlling process variables based on the same equipment and technology.

The present invention has been proposed to solve the above problems of the prior art, and an object thereof is to provide a semiconductor manufacturing apparatus capable of more efficiently adjusting process parameters.

1 is a cross-sectional view schematically showing a semiconductor manufacturing apparatus according to an embodiment of the present invention.

Figure 2 is a schematic diagram illustrating a case of adjusting the temperature, one of the process variables by adjusting the surface curvature of the wafer back surface.

3 is a view illustrating a change in pattern size in an etching process due to a change in surface curvature of a wafer back surface.

Explanation of symbols on the main parts of the drawings

100: wafer 101: wafer front

102 wafer back 200 support

201: bend

In order to achieve the above object, the present invention includes a support for supporting a wafer, the support having a bend corresponding to the bend of the back surface of the wafer to increase the area in contact with the wafer supported thereon A semiconductor manufacturing apparatus is provided.

Preferably, heat or power is transferred to the wafer through the support, and the support includes any one of a chuck, a cathode, or an anode.

The present invention is to have a kind of bending on the back of the wafer to more accurately and easily control the process parameters, such as temperature. In addition, it is possible to adjust process variables differently according to each part of the front side and the back side corresponding to the wafer where the pattern is substantially formed in the etching process or the deposition process, so as to correspond to the back side of the wafer having the bend in the support such as the chuck where the wafer is located. Make sure

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the technical idea of the present invention. do.

1 is a cross-sectional view schematically illustrating a semiconductor manufacturing apparatus according to an embodiment of the present invention.

Referring to FIG. 1, a semiconductor manufacturing apparatus including a support 200 for supporting a wafer is provided, and the support 200 is a back surface of a wafer in order to increase an area in contact with the wafer 100 supported thereon. It has a curvature corresponding to the curvature of 102.

Examples of the support 200 include a chuck, a cathode, or an anode, which is a specific portion of a circular prober that fixes the wafer 100 and applies an appropriate temperature when testing the wafer 100.

A process such as deposition or etching is performed on the front surface 101 of the wafer 100, and the rear surface 102 is in contact with the support 200. During the process, predetermined power and heat are provided to the wafer backside 102 through the support 200. In this case, the support 200 is connected to a cathode electrode or to a heating wire.

In the present invention, when the predetermined process is performed on the front surface 101 of the wafer 100, the rear surface 102 (or the rear surface) of the wafer 100 is used to more precisely control the control of the process variables. As such, it is possible to control the temperature or power differently according to a specific part without simply applying the same power (or bias) or temperature to the entire rear surface 102. To this end, to have a bend 201 in the back surface 102 of the wafer 100 in contact with the support 200, the support 200 is also bent in the wafer back surface 102 to make contact with the wafer back surface 102 Has a curvature corresponding to 201.

In the prior art, only the temperature of the support 200 on which the wafer 100 is placed, for example, the chuck, is adjusted, and the curvature 201, or roughness of the wafer backside 102 is not used to adjust the process variables. In the present invention, in the case of a process of adjusting a process variable such as temperature by directly contacting the wafer 100, the temperature of the support 200 on which the wafer 100 is placed may be adjusted. In difficult cases, the bending of the wafer backside 102 is controlled to obtain the process temperature.

This is possible because the curvature of the wafer backside 102 affects the contact area, which is an important factor in transferring the temperature at the front side 101 where the reaction takes place.

2 is a schematic diagram illustrating a case in which a temperature, which is one of process variables, is adjusted by adjusting surface curvature of a wafer back surface.

Referring to FIG. 2, a wafer 100 having a bend 201 on its rear surface 102 is positioned on a support 200, and the wafer 100 and the support 200 are bent 201 corresponding to each other. ), The contact area is increased. On the other hand, the plasma 300 is excited above the wafer front surface 101 over etching or deposition.

2 is an enlarged cross-sectional view of a portion 'a' on the left side. Here, in the cross-sectional view of the upper portion, the bent portion 201 corresponding to each other in the portion where the wafer 100 and the support 200 are in contact with each other shows a large contact area, and in the lower cross-sectional view, the wafer 100 and the support 200 are shown. The curved portions 201 corresponding to each other at the contact portion thereof are relatively weak compared to the cross-sectional view of the upper portion thereof, indicating a state where the contact area is small.

At this time, when heat is applied to the wafer 100 through the support 200, the temperature at the front surface of the wafer 101 is relatively higher in the upper case where the contact area is larger than the lower case.

Therefore, even if the process variable in the same chamber, the fine adjustment is possible through the bending control in the wafer back surface 102.

3 is a view illustrating a change in pattern size in an etching process due to a change in surface curvature of a wafer back surface.

Referring to FIG. 3, an example of etching a sample prepared by fixing all other process variables and differently preparing only the bends on the back surface of the wafer is illustrated. Due to the large curvature on the back of the wafer, the difference in temperature occurs at the front of the wafer during the actual process. The critical dimension (hereinafter referred to as CD) of the bar type pattern at a relatively high temperature at the front of the wafer is low. It can be seen that it is reduced by about 12nm than the case (by the width of the hole, the case of high temperature is about 12nm larger). In addition, a slight bowing (c) occurs in the etched profile when the back curve is small, but at high temperature, the bowing hardly occurs (d), and it has a vertical (Vertical) etching profile.

In the above example, a dry etching process using plasma is used as an example, but it is also applicable to a deposition process in addition to the etching process. That is, it can be used for temperature control in a deposition process such as chemical vapor deposition (CVD) or physical vapor deposition (PVD). Therefore, the deposition rate during deposition and the degree of densification of the film are controlled.

In the etching process, the backside of the wafer may be used to adjust the etching profile and the CD.

On the other hand, it is possible to overcome the hardware limitations in the deposition or etching process by adjusting the bending of the back surface of the wafer. For example, in the etching process, the temperature of the chuck (cathode) is in the range of -20 ° C to 80 ° C due to the hardware limit. You can broaden your range. Increasing the temperature range here refers to the effective temperature applied to the wafer rather than the temperature actually being applied to the chuck.

To increase the curvature of the back surface of the wafer, a wet or dry etching method, or a chemical mechanical polishing (CMP) process may be applied. Here, the chemical used in the case of applying wet etching may be divided into an acidic solution and an alkaline solution, and the acidic solution is a chemical of nitric acid + acetic acid + hydrofluoric acid. As the basic solution, KOH or NaOH is used.

The present invention, as described above, can facilitate the adjustment of process parameters by increasing the curvature on the back of the paper (to have curvature on the back of the wafer) to increase the contact area between the wafer and the support. It has been found through examples that the hardware limitations can be overcome to some extent and the process control can be precisely achieved.

Although the technical idea of the present invention has been described in detail according to the above preferred embodiment, it should be noted that the above-described embodiment is for the purpose of description and not of limitation. In addition, those skilled in the art will understand that various embodiments are possible within the scope of the technical idea of the present invention.

The present invention as described above can expect the following effects.

One). A new process variable called curvature on the back of the wafer can be obtained in every process where the surface temperature of the wafer is adjusted through the temperature of the support (chuck, cathode, anode, etc.) on which the wafer is placed.

2). When the wafer is limited (eg when the cathode temperature in the visual reactor can no longer be raised or lowered), the curvature of the wafer backside can be adjusted to control the temperature of the wafer front where the reaction actually occurs. That is, the limitations of the hardware can be overcome to some extent.

3). When several processes are performed in the same reactor and there is a requirement to proceed at different temperatures, it is possible to overcome this by adjusting the bend of the wafer back without changing the hardware. The loss can be reduced.

Claims (7)

And a support for supporting a wafer, wherein the support has a curvature corresponding to the curvature of the back surface of the wafer to increase an area in contact with the wafer supported thereon. The method of claim 1, The semiconductor manufacturing apparatus, characterized in that heat or power is transferred to the wafer through the support. The method of claim 1, The support is a semiconductor manufacturing apparatus, characterized in that it comprises any one of the Chuck (Cathode) or the anode (Anode). The method of claim 1, The back surface of the wafer, the semiconductor manufacturing apparatus, characterized in that the surface curved through the wet etching, dry etching or chemical mechanical polishing process. The method of claim 1, And controlling the etch profile on the front surface of the wafer by adjusting the surface curvature of the back surface of the wafer. The method of claim 1, And adjusting the surface curvature of the back surface of the wafer to control the thickness or film density of the film deposited on the front surface of the wafer. The method of claim 1, And controlling the surface curvature of the back surface of the wafer to control the pattern size on the front surface of the wafer.