CN214123831U

CN214123831U - Edge ring height measuring device

Info

Publication number: CN214123831U
Application number: CN202023016828.6U
Authority: CN
Inventors: 蔡楚洋; 吴狄; 连增迪
Original assignee: Advanced Micro Fabrication Equipment Inc Shanghai
Current assignee: Advanced Micro Fabrication Equipment Inc Shanghai; Advanced Micro Fabrication Equipment Inc
Priority date: 2020-12-15
Filing date: 2020-12-15
Publication date: 2021-09-03
Anticipated expiration: 2030-12-15

Abstract

The utility model provides an edge ring height measurement device, including putting the bearing dish that has the setpoint on electrostatic chuck to and bear the imaging device on the dish, acquire the image of edge ring many times through imaging device, then calculate the height or the thickness change of edge ring after data processing, change data and be favorable to the adjustment to edge ring loss, utilize the measurement to different regional multiple points can reduce the error, need not destroy original vacuum environment, greatly reduced because of the dead time that the adjustment of edge ring consumes.

Description

Edge ring height measuring device

Technical Field

The utility model relates to a plasma sculpture technical field especially relates to an edge ring height measurement device.

Background

Micromachining of semiconductor substrates or substrates is a well-known technique that may be used to fabricate, for example, semiconductors, flat panel displays, Light Emitting Diodes (LEDs), solar cells, and the like. An important step in microfabrication is a plasma processing process step, which is performed inside a reaction chamber into which process gases are introduced. An rf source is inductively and/or capacitively coupled to the interior of the chamber to excite the process gases to form and maintain a plasma. Inside the reaction chamber, the exposed substrate is supported by the lower electrode assembly and fixed in a fixed position by some clamping force to ensure the safety of the substrate and high yield of processing in the process.

The lower electrode assembly comprises an electrostatic chuck for fixing a substrate, a base for supporting the electrostatic chuck, and an edge ring assembly arranged around the base, and is used for supporting and fixing the substrate and controlling the temperature, electric field distribution and the like of the substrate in the process of processing the substrate.

In the prior art, the edge ring assembly can be used to adjust the bombardment effect of plasma on the substrate, and when the edge ring is worn in the using process, the pre-designed plasma etching condition can be influenced, so that the uniformity is reduced.

The general solution to this situation is two, one is to replace the edge ring each time there is damage, and one is to change the edge ring parameters to compensate. The first method is costly and causes a stoppage of production every time the vacuum chamber is opened, and the second method has problems of timing of change and amount of change, and if the vacuum chamber is opened every time the edge ring rise is measured, the production is also stopped, so it is necessary to accurately measure the edge ring change with the dead time as small as possible.

SUMMERY OF THE UTILITY MODEL

In order to solve the technical problem, the utility model provides an edge ring height measuring device for measure the altitude variation around the edge ring of electrostatic chuck setting on the electrostatic chuck of plasma reaction intracavity, include:

an imaging device for acquiring an image of the edge ring;

the bearing plate of the imaging device can be placed on the electrostatic chuck, and the bearing plate is provided with positioning points.

Optionally, a light source is also included.

Optionally, the imaging apparatus includes:

a camera positioned on the bearing disc, wherein the lens of the camera can be aligned with the upper surface of the edge ring;

and the control device is connected with the camera and used for wireless communication with external equipment.

Optionally, the number of the cameras is at least four, and the cameras respectively correspond to different areas of the edge ring.

Optionally, the imaging device comprises a planar mirror assembly located on the carrier tray.

Optionally, the plane mirror assembly includes a plane mirror and a support, and the imaging device further includes an adjusting device electrically connected to the support, for adjusting an inclination angle of the plane mirror.

Optionally, the imaging apparatus further comprises an image analyzer located outside the reaction chamber, and the image analyzer can acquire an image of the edge ring formed by the flat mirrors through a window of the reaction chamber.

Optionally, the imaging device is fixedly connected to the carrying tray, and the positioning point is used to ensure that the images acquired by the imaging device in two adjacent times belong to the same region of the edge ring.

Optionally, the edge ring comprises a focus ring.

Further, a plasma processing system is provided, comprising a process chamber, a transfer chamber and a storage chamber, comprising the measurement device of any of the above.

Optionally, the measuring device can be transferred between the process chamber and the storage chamber via the transfer chamber.

The utility model has the advantages that: the utility model provides a measure device of edge ring height, can carry out data acquisition to the change of edge ring height, utilize the measurement to different regional multiple points can reduce the error, predict the damage degree of edge ring, adjustment for follow-up edge ring provides more accurate support, and, measuring device can put on the inside substrate frame of frame, send into the reaction chamber through the manipulator and take out after measuring, then borrow communication module and external system and carry out data transmission, need not destroy original vacuum environment, greatly reduced because of the dead time that the adjustment of edge ring consumes, and the production efficiency is improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 shows a schematic structural diagram of a capacitively-coupled plasma processing apparatus;

FIG. 2 illustrates an embodiment of an edge ring height measurement device;

FIG. 3 illustrates an edge ring height measurement apparatus of another embodiment.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be clearly and completely described below with reference to the accompanying 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. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Fig. 1 shows a schematic view of a capacitively coupled plasma processing apparatus, which includes an evacuable reaction chamber 100 surrounded by an outer wall 10. The reaction chamber 100 is used to process a substrate 103. The reaction chamber comprises a lower electrode assembly inside, and is used for supporting the substrate and controlling the substrate temperature, the electric field and other factors influencing the substrate processing. The lower electrode assembly comprises a base 101 for bearing an electrostatic chuck 102, a temperature control device is arranged in the base 101 for realizing the temperature control of an upper substrate, the electrostatic chuck 102 for bearing a substrate 103, and a direct current electrode is arranged in the electrostatic chuck, and the direct current electrode generates direct current adsorption between the back surface of the substrate and the bearing surface of the electrostatic chuck so as to realize the fixation of the substrate. An edge ring assembly 20 is provided around the periphery of the pedestal and electrostatic chuck for adjusting the temperature, electric field distribution, etc. at the edge region of the substrate. Disposing a plasma confinement ring 108 around the edge ring assembly 20, between the edge ring assembly 20 and the chamber sidewall, for confining a plasma to the reaction region while allowing gas to pass therethrough; the grounding ring 109, located below the plasma confinement ring, functions to provide electric field shielding to prevent plasma leakage. A bias RF power supply, typically applying a bias RF signal to the lower electrode assembly, controls the direction of plasma bombardment.

In the capacitively-coupled plasma processing apparatus shown in fig. 1, an upper electrode assembly is included in addition to a lower electrode assembly, and the upper electrode assembly includes a gas shower head 30 for introducing a process gas in a gas supply apparatus into the reaction chamber. And a high-frequency radio frequency power source applies a high-frequency radio frequency signal to at least one of the upper electrode assembly or the lower electrode assembly so as to form a radio frequency electric field between the upper electrode assembly and the lower electrode assembly, and excites the process gas in the reaction cavity into plasma, thereby realizing the treatment of the plasma on the substrate to be treated.

In an edge ring measuring apparatus as shown in fig. 2, the edge ring assembly 20 includes a focus ring 201, which can adjust the shape of the plasma to make the etching more uniform, but as the number of reaction times increases, the focus ring 201 will be eroded by the plasma to change the surface topography, especially the height, of the focus ring 201, and thus the shape of the plasma will also change, so in order to ensure the uniformity of etching a plurality of substrates, it is necessary to compensate the focus ring 201 by inserting pins 202 into the insert ring 203, so that the degree of adjustment of the focus ring 201 to the plasma is maintained constant. However, in order to obtain the adjustment amount of the focus ring 201, the vacuum chamber is usually opened, the actual loss of the focus ring 201 is measured, and the vacuum pumping operation is performed after the adjustment, so that the etching process is stopped, and the production efficiency is reduced. In the edge ring height measuring device of the present invention, the carrier plate 112 located on the electrostatic chuck 102 is not limited to a plate shape, but may be other polygons, in some embodiments, the size and shape of the carrier plate 112 are the same as those of the substrate 103, and the carrier plate 112 has positioning points, so that the position can be controlled when the carrier plate is placed on the electrostatic chuck 102 every time, for example, the carrier plate 112 can be controlled to be placed at the last time and the carrier plate can be controlled to rotate at the same angle every time. An imaging device is placed on the carrying tray 112, in this embodiment, the imaging device includes a camera 111, the lens of the camera 111 can be aligned with the upper surface of the focusing ring 201, so as to capture the damage degree of the focusing ring 201 each time an image is acquired, the height change of the focusing ring 201 can be calculated by comparing the captured images, in some embodiments, the camera 111 is located at the edge of the carrying tray 112, and is as close to the focusing ring 201 as possible; in other embodiments, the lens axis of the camera 111 may also be located on the diameter of the carrier plate 112 of the disc-shaped embodiment, such that its lens can be directed to a local area of the focus ring 201. The imaging device further comprises a control device 114 for controlling the shooting time of the camera 111 and transmitting the image data to an external system for calculating the height change of the focus ring 201, in some embodiments, the control device 114 may be connected to the external system in a wireless communication manner to implement shooting control and data transmission, or may automatically shoot through a program written in uniformity. In other embodiments, the number of the cameras 111 may be 4, and the cameras 111 are uniformly distributed on the edge of the carrier tray 112, so that the shot data may cover the whole upper portion of the focus ring 201, or the cameras 111 may be arranged according to the position where the actual focus ring 201 is easily damaged, so that the 4 cameras are aligned to different positions on the focus ring 201, which are easily damaged. The measuring device may further comprise a light source 113 for providing light compensation in the reaction chamber in order to improve the shooting resolution.

Fig. 3 shows another embodiment of the measuring apparatus of the present invention, which is different from the first embodiment in that the imaging device includes a plane mirror assembly for measuring the change of height or thickness after reflecting the upper image of the focusing ring 201 to the outside of the reaction chamber 100, and in this embodiment, the plane mirror assembly includes a plane mirror 211, as shown by the dotted line, the plane mirror 211 can reflect the upper image of the focusing ring 201 to the outside of the reaction chamber 100 through a window on the outer wall 10, and then the reflected image is calculated by the image analyzer 216, and in some embodiments, the window can be a substrate 13 transferring window of the reaction chamber 100. The flat mirror assembly further includes a support 215 fixedly connected to the flat mirror 211 and wirelessly connected to an external system to control the deflection angle of the flat mirror 211 to select an optimal reflection angle for obtaining a clear image.

Further, the utility model also provides a plasma processing system, including the technology process chamber for process processes such as sculpture, transmission chamber for hold the manipulator and convey substrate or other equipment from each cavity, the storage chamber for deposit substrate or other equipment and supply the manipulator to get and put, process chamber, transmission chamber and storage chamber can be in the same vacuum environment. The processing system also comprises any one of the edge ring height measuring devices, the measuring devices can be stored in the storage cavity, when the edge ring height measuring device is used, the measuring devices are taken out from the storage cavity through the mechanical arm in the transmission cavity and put into the corresponding process processing cavity, and the storage cavity is put back after the measurement, so that the edge ring height measurement can be realized without opening the whole system to destroy the vacuum environment.

Use the utility model discloses a change of edge ring is measured to edge ring height measuring device mainly includes following step:

before reaction, putting any one edge ring height measuring device into a plasma reaction cavity to obtain a height image of the edge ring;

after the reaction, putting the arbitrary edge ring height measuring device into a plasma reaction cavity to obtain a height image of the edge ring;

and step three, comparing the images obtained in the step one and the step two, and calculating the height change of the edge ring.

In some embodiments, in the first step and the second step, the average value of the height of the edge ring in the same area may be calculated after images of the same area are captured for multiple times, or the average value of the overall height change of the edge ring may be calculated after images of different areas are captured, or a certain area is selected to be captured for multiple times to calculate the average value, and then the average values of multiple different areas are averaged to calculate the height value of the edge ring, specifically, positioning points on the bearing disc 112 may be used to enable the imaging device to be aligned to the same area each time, or to control the rotation fixing angle to be aligned to different areas. In other embodiments, the height change calculated in the third step is an edge ring height change obtained by taking a difference between the initial edge ring height value obtained in the first step and the edge ring height value obtained in the second step after each reaction; step one and step two can also be regarded as images acquired before and after a single reaction, and step three is the edge ring height change calculated for the images acquired two times adjacent to the single reaction.

For the obtained edge ring image, the height conversion can be carried out through a pixel unit without obtaining an actual height value, then the converted relative height or the change of the relative height is coupled with a compensation value which needs to be adjusted by the edge ring, an external adjusting system controls the inserting pin 202 according to a measuring result fed back each time, and in some embodiments, the inserting pin 202 can have a lifting function and lifts the edge ring according to the measuring result to carry out physical height compensation; in other embodiments, the insert pin 202 may be a conductor, one end of which is in contact with the edge ring and the other end of which is connected to a set of tuning capacitors, or both the insert pin 202 and the insert ring 203 may be conductors, and the insert pin 202 does not need to penetrate the insert ring 203, but only needs to contact the insert ring 203 with the edge ring, and one end of the insert pin 202 is in contact with the insert ring 203 and the other end of which is connected to a set of tuning capacitors, and the capacitors are tuned according to the measurement results to change the overall capacitance value, so as to perform electrical compensation of the edge ring. Therefore, the technical effect of maintaining the plasma etching uniformity without opening the whole vacuum system is achieved.

The utility model discloses an edge ring height measuring device is not limited to the plasma processing apparatus who is applied to above-mentioned embodiment, also can be suitable for in other plasma processing apparatus, and it is no longer repeated here.

While the present invention has been described in detail with reference to the preferred embodiments thereof, it should be understood that the above description should not be taken as limiting the present invention. Numerous modifications and alterations to the present invention will become apparent to those skilled in the art upon reading the foregoing description. Accordingly, the scope of the invention should be limited only by the attached claims.

Claims

1. An edge ring height measuring device for measuring the height change of an edge ring disposed around an electrostatic chuck on the electrostatic chuck in a plasma reaction chamber, comprising:

an imaging device for acquiring an image of the edge ring;

2. The measurement device of claim 1, further comprising a light source.

3. The measurement apparatus of claim 1, wherein the imaging device comprises:

4. A measuring apparatus according to claim 3, wherein the number of said cameras is at least four, each corresponding to a different area of said edge ring.

5. A measuring apparatus according to claim 1, wherein the imaging device comprises a planar mirror assembly located on the carrier tray.

6. A measuring apparatus according to claim 5, wherein the planar mirror assembly comprises a planar mirror and a support, the imaging device further comprising adjustment means electrically connected to the support for adjusting the tilt angle of the planar mirror.

7. A measurement device according to claim 6, wherein the imaging means further comprises an image analyser located outside the reaction chamber, the image analyser being operable to obtain an image of the edge ring formed by the planar mirrors through a window of the reaction chamber.

8. The measuring apparatus according to claim 1, wherein the imaging device is fixedly connected to the carrier tray, and the positioning points are used to ensure that the images obtained by the imaging device in two adjacent times belong to the same region of the edge ring.

9. The measurement device of claim 1, wherein the edge ring comprises a focus ring.

10. A plasma processing system comprising a process chamber, a transfer chamber and a storage chamber, comprising a measurement apparatus according to any of claims 1-9.

11. The processing system of claim 10, wherein the measuring device is transferable through the transfer chamber between the process chamber and the storage chamber.