CN-121983492-A - Etching equipment and compensation method for focus ring etching compensation

CN121983492ACN 121983492 ACN121983492 ACN 121983492ACN-121983492-A

Abstract

The application provides etching equipment and a compensation method for focus ring etching compensation, and relates to the technical field of semiconductor etching. The etching structure comprises a base, an electrostatic chuck, a focusing ring and a cover ring. The detection structure comprises a light source, a first lens, a second lens and a detection module, wherein the light source outputs detection light, the first lens transmits the detection light to the focusing ring, the second lens receives the detection light transmitted by the focusing ring and reflects the detection light to the detection module, the detection module obtains the light intensity of the detection light, and the detection module obtains the etching compensation value of the focusing ring based on the light intensity, namely the etched height of the focusing ring is obtained. The adjusting structure lifts the focusing ring based on the etching compensation value, so that the etching compensation of the focusing ring is realized, and the etching effect of the wafer is ensured.

Inventors

DONG QI
YIN GEHUA
LIU HAIYANG
YE PENG
LI BAISHUN
HU DONGDONG
SHI XIAOLI
XU KAIDONG

Assignees

江苏鲁汶仪器股份有限公司

Dates

Publication Date: 20260505
Application Date: 20241029

Claims (13)

1. An etching apparatus for focus ring etch compensation, comprising: the etching structure is used for realizing etching of the wafer and comprises a base, an electrostatic chuck, a focusing ring and a cover ring, wherein the electrostatic chuck is positioned on the base, the cover ring surrounds the base, and the focusing ring is positioned on the cover ring and surrounds the electrostatic chuck; the detection structure comprises a light source, a first lens, a second lens and a detection module, wherein the light source outputs detection light, the first lens transmits the detection light to the focusing ring, and the second lens receives the detection light transmitted by the focusing ring and transmits the detection light transmitted by the focusing ring to the detection module; the detection module acquires the light intensity of the detection light transmitted by the focusing ring, and acquires an etching compensation value of the focusing ring based on the light intensity, wherein the etching compensation value is the height of an etched part of the focusing ring; and the adjusting structure is used for lifting the focusing ring based on the etching compensation value to realize the etching compensation of the focusing ring.
2. The focus ring etching-compensated etching apparatus of claim 1, wherein the cover ring has N aperture groups therein, N being equal to or greater than 1, the aperture groups including an aperture circumferentially arranged around the base and a second aperture, and a line connecting the first aperture and the second aperture passing through a center position of the focus ring; The first lens is located in the first hole, and the second lens is located in the second hole.
3. The focus ring etch-compensated etch apparatus of claim 2, wherein the first lens and the second lens are centered at the same height and the line is flush with the initial upper surface of the focus ring.
4. The focus ring etch-compensated etch device of claim 3, wherein the first lens plane has a first angle with a first direction, the second lens plane has a second angle with the first direction, the first angle and the second angle being complementary; the value range of the first included angle is 0-90 degrees, the end point value is not included, and the first direction is parallel to the plane where the electrostatic chuck is located.
5. The focus ring etch-compensated etch apparatus of claim 4 wherein the first angle has a value of 45 ° and the second angle has a value of 135 °.
6. The focus ring etching compensation etching device according to claim 1, wherein the adjusting structure comprises M lifting pins, M is equal to or greater than 3; The cover ring is provided with M third holes circumferentially distributed around the base, the third holes extend upwards from the bottom of the cover ring to the bottom of the focusing ring along a second direction, and the second direction is parallel to the distribution direction of the base and the electrostatic chuck; and the M lifting pins are respectively positioned in the M third holes and used for lifting the focusing ring to realize etching compensation of the focusing ring.
7. The focus ring etch compensated etch apparatus of claim 1, further comprising: the first chamber is a vacuum chamber, and the etching structure is positioned in the first chamber; the second chamber is a non-vacuum chamber and is connected with the first chamber, and the light source and the detection module are positioned in the second chamber.
8. The focus ring etch compensated etch apparatus of claim 7, further comprising: the first light-transmitting window is positioned at the junction of the first cavity and the second cavity and corresponds to the first lens, and the detection light is transmitted to the first lens through the first light-transmitting window; the second light-transmitting window is positioned at the junction of the first cavity and the second cavity and corresponds to the second lens, and the detection light is transmitted to the detection module through the second light-transmitting window.
9. The focus ring etch compensated etch apparatus of any of claims 1-8, wherein the etch structure comprises: An intermediate ring positioned between the cover ring and the electrostatic chuck, and having an upper surface lower than an upper surface of the focus ring.
10. A compensation method for realizing etching compensation of a focusing ring in etching equipment is characterized by comprising an etching structure, a detection structure and an adjustment structure, wherein the etching structure is used for realizing etching of a wafer and comprises a base, an electrostatic chuck, a focusing ring and a cover ring, the electrostatic chuck is arranged on the base, the cover ring surrounds the base, the focusing ring is arranged on the cover ring and surrounds the electrostatic chuck, the detection structure comprises a light source, a first lens, a second lens and a detection module, and the compensation method comprises the following steps: The light source outputs detection light; The first lens transmits the detection light to the focusing ring, and the second lens receives the detection light transmitted by the focusing ring and transmits the detection light transmitted by the focusing ring to the detection module; The detection module acquires the light intensity of the detection light transmitted by the focusing ring and acquires an etching compensation value of the focusing ring based on the light intensity, wherein the etching compensation value is the height of an etched part of the focusing ring; and the adjusting structure lifts the focusing ring based on the etching compensation value to realize the etching compensation of the focusing ring.
11. The compensation method of claim 10, wherein the detecting module obtains a light intensity of the detected light transmitted through the focus ring, and obtaining the etch compensation value of the focus ring based on the light intensity comprises: Moving the light source in a first direction, wherein the first direction is parallel to a plane of the electrostatic chuck; In the process of moving the light source, the detection module acquires the light intensity of the detection light transmitted by the focusing ring; When the light intensity of the detection light is preset, acquiring the displacement of the light source, wherein the displacement of the light source is equal to the etching compensation value of the focusing ring; The preset light intensity is the light intensity when the transmission path of the detection light is flush with the upper surface of the focusing ring.
12. The compensation method of claim 10, wherein the detecting module obtains a light intensity of the detected light transmitted through the focus ring, and obtaining the etch compensation value of the focus ring based on the light intensity comprises: synchronously lifting the first lens and the second lens along a second direction, wherein the second direction is parallel to the arrangement direction of the base and the electrostatic chuck; In the lifting process of the first lens and the second lens, the detection module obtains the light intensity of the detection light transmitted by the focusing ring; If the light intensity of the detection light is preset light intensity, obtaining the displacement of the first lens, wherein the displacement of the first lens is equal to the etching compensation value of the focusing ring; The preset light intensity is the light intensity when the transmission path of the detection light is flush with the upper surface of the focusing ring.
13. The compensation method of claim 10, wherein the detecting module obtains a light intensity of the detected light transmitted through the focus ring, and obtaining the etch compensation value of the focus ring based on the light intensity comprises: Lifting the focusing ring along a second direction, wherein the second direction is parallel to the arrangement direction of the base and the electrostatic chuck; In the lifting process of the focusing ring, the detection module acquires the light intensity of the detection light transmitted by the focusing ring; if the light intensity of the detection light is preset light intensity, obtaining the displacement of the focusing ring, wherein the displacement of the focusing ring is equal to the etching compensation value of the focusing ring; The preset light intensity is the light intensity when the transmission path of the detection light is flush with the upper surface of the focusing ring.

Description

Etching equipment and compensation method for focus ring etching compensation Technical Field The application relates to the technical field of semiconductor etching, in particular to a compensation method of etching equipment for focus ring etching compensation. Background As semiconductor devices are being developed toward smaller dimensions and higher precision, wafer processing is increasingly demanding on dry etching techniques, equipment, and the like. The inductively coupled plasma etching technology (Inductively Coupled Plasma, abbreviated as ICP) has the advantages of high etching rate, good directivity, high selection ratio, high contour control precision and the like, and is widely applied to various large wafer processing factories. However, for ICP etching equipment, the focus ring is used to adjust the etch rate or etch profile near the radially outer edge of the wafer, and is exposed to the plasma for a long period of time. Therefore, after a period of time, the focus ring is etched by the plasma, and the shape of the focus ring changes to change the electric field near the wafer edge, which affects the etching uniformity near the wafer edge. Disclosure of Invention In view of the above, the application provides an etching device and a compensation method for focus ring etching compensation, and the scheme is as follows: an etching apparatus for focus ring etch compensation, comprising: the etching structure is used for realizing etching of the wafer and comprises a base, an electrostatic chuck, a focusing ring and a cover ring, wherein the electrostatic chuck is positioned on the base, the cover ring surrounds the base, and the focusing ring is positioned on the cover ring and surrounds the electrostatic chuck; the detection structure comprises a light source, a first lens, a second lens and a detection module, wherein the light source outputs detection light, the first lens transmits the detection light to the focusing ring, and the second lens receives the detection light transmitted by the focusing ring and transmits the detection light transmitted by the focusing ring to the detection module; the detection module acquires the light intensity of the detection light transmitted by the focusing ring, and acquires an etching compensation value of the focusing ring based on the light intensity, wherein the etching compensation value is the height of an etched part of the focusing ring; and the adjusting structure is used for lifting the focusing ring based on the etching compensation value to realize the etching compensation of the focusing ring. Optionally, the cover ring is provided with N open hole groups, N is greater than or equal to 1, the open hole groups comprise an open hole and a second open hole which are circumferentially arranged around the base, and a connecting line of the first open hole and the second open hole passes through the center position of the focusing ring; The first lens is located in the first hole, and the second lens is located in the second hole. Optionally, the center positions of the first lens and the second lens are located at the same height, and the connecting line is flush with the initial upper surface of the focusing ring. Optionally, the plane of the first lens has a first included angle with a first direction, the plane of the second lens has a second included angle with the first direction, and the first included angle and the second included angle are complementary; the value range of the first included angle is 0-90 degrees, the end point value is not included, and the first direction is parallel to the plane where the electrostatic chuck is located. Optionally, the value of the first included angle is 45 °, and the value of the second included angle is 135 °. Optionally, the adjusting structure comprises M lifting pins, wherein M is more than or equal to 3; The cover ring is provided with M third holes circumferentially distributed around the base, the third holes extend upwards from the bottom of the cover ring to the bottom of the focusing ring along a second direction, and the second direction is parallel to the distribution direction of the base and the electrostatic chuck; and the M lifting pins are respectively positioned in the M third holes and used for lifting the focusing ring to realize etching compensation of the focusing ring. Optionally, the method further comprises: the first chamber is a vacuum chamber, and the etching structure is positioned in the first chamber; the second chamber is a non-vacuum chamber and is connected with the first chamber, and the light source and the detection module are positioned in the second chamber. Optionally, the method further comprises: the first light-transmitting window is positioned at the junction of the first cavity and the second cavity and corresponds to the first lens, and the detection light is transmitted to the first lens through the first light-transmitting window; the second light-tra