CN-121983493-A - Etching equipment with imaging system and detection method

CN121983493ACN 121983493 ACN121983493 ACN 121983493ACN-121983493-A

Abstract

The application provides etching equipment with an imaging system and a detection method, and relates to the technical field of semiconductor etching, wherein the etching equipment comprises: the etching structure comprises a base, an electrostatic chuck, a focusing ring and a cover ring, wherein the imaging structure is positioned on the cover ring and used for acquiring a contour image of the focusing ring, acquiring the position deviation of the focusing ring relative to the electrostatic chuck based on the contour image of the focusing ring, and the calibration structure moves the focusing ring based on the position deviation so as to change the position of the focusing ring, further eliminate the position deviation and ensure the position accuracy of the focusing ring so as to ensure the etching effect of a wafer. Moreover, the imaging system is integrated on the cover ring, so that the etching equipment can realize the detection of the position deviation of the focusing ring on the basis of not damaging the vacuum condition of the etching cavity, avoid a series of problems, such as particle problems and the like, possibly caused by opening the etching cavity, and further ensure the etching effect of the wafer.

Inventors

YIN GEHUA
DONG QI
LIU HAIYANG
YE PENG
SHI XIAOLI
TAO ZHENG
HU DONGDONG
XU KAIDONG

Assignees

江苏鲁汶仪器股份有限公司

Dates

Publication Date: 20260505
Application Date: 20241029

Claims (12)

1. An etching apparatus having an imaging system, comprising: the etching structure is used for realizing the etching of the workpiece 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 imaging system is positioned on the cover ring and is used for acquiring a contour image of the focusing ring and acquiring the position deviation of the focusing ring relative to the electrostatic chuck based on the contour image of the focusing ring; And a calibration structure that moves the focus ring based on the positional deviation, eliminating the positional deviation.
2. The etching apparatus with imaging system of claim 1, wherein the positional deviations comprise a first positional deviation and a second positional deviation; The first position deviation is the deviation of the central position of the focusing ring and the central position of the electrostatic chuck on a first plane, the second position deviation is the deviation of the central position of the focusing ring and the central position of the electrostatic chuck on a second plane, the first plane is perpendicular to the mounting plane of the electrostatic chuck, the second plane is parallel to the mounting plane of the electrostatic chuck, and the first plane and the second plane are perpendicular; The imaging system comprises N imaging modules which are circumferentially distributed around the base, wherein N is more than or equal to 3, each imaging module comprises a first imaging module and a second imaging module, the first imaging module is opposite to the side part of the focusing ring and is used for acquiring a side contour image of the focusing ring and acquiring the first position deviation based on the side contour image of the focusing ring, and the second imaging module is opposite to the bottom of the focusing ring and is used for acquiring a bottom contour image of the focusing ring and acquiring the second position deviation based on the bottom contour image of the focusing ring.
3. The etching apparatus with an imaging system according to claim 2, wherein the first imaging module includes a first lens group, a first image sensing unit, a first image processing unit, and a first signal transmission unit, wherein the first lens group acquires a first optical signal carrying side profile information of the focus ring and transmits to the first image sensing unit, the first image sensing unit converts the first optical signal into a first electrical signal and transmits to the first image processing unit, and the first image processing unit acquires the first positional deviation based on the first electrical signal; The second imaging module comprises a second lens group, a second image sensing unit, a second image processing unit and a second signal transmission unit, wherein the second lens group acquires a second optical signal and transmits the second optical signal to the second image sensing unit, the second optical signal carries the bottom profile information of the focusing ring, the second image sensing unit converts the second optical signal into a second electric signal and transmits the second electric signal to the second image processing unit, and the second image processing unit acquires the second position deviation based on the second electric signal; the first signal transmission unit also provides electric energy for each component in the first imaging module, and the second signal transmission unit also provides electric energy for each component in the second imaging module.
4. The etching apparatus with an imaging system according to claim 3, wherein the first image sensing unit is a charge coupled device, the first image processing unit is an image signal processing chip, the second image sensing unit is a charge coupled device, and the second image processing unit is an image signal processing chip.
5. The etching apparatus with an imaging system according to claim 3, wherein the first imaging module and the second imaging module are identical in structure, further comprising a moving coil for focusing of the lens group, a color filter for color and brightness of the imaging module, a holder, and a flash unit for illuminating the focus ring to generate the first optical signal and the second optical signal.
6. The etching apparatus of claim 2, wherein the imaging system comprises 3 imaging modules circumferentially arranged around the base.
7. The etching apparatus with imaging system of claim 2, wherein the calibration structure comprises a lift structure and a robot; The cover ring is provided with N open holes circumferentially distributed around the base, the open holes extend upwards from the bottom of the cover ring to the bottom of the focusing ring along a first direction, and the first direction is parallel to the distribution direction of the base and the electrostatic chuck; the lifting structure comprises N lifting pins, the N lifting pins are respectively positioned in the N holes, and the focusing ring is lifted based on the first position deviation, so that the first position deviation is eliminated; the manipulator moves the focus ring based on the second positional deviation, eliminating the second positional deviation.
8. The detection method is characterized by comprising an etching structure, an imaging system and a calibration structure, wherein the etching structure is used for realizing etching of a wafer, the etching structure comprises a base, an electrostatic chuck, a focusing ring and a cover ring, the electrostatic chuck is positioned on the base, the cover ring surrounds the base, the focusing ring is positioned on the cover ring and surrounds the electrostatic chuck, the imaging system is positioned on the cover ring, and the detection method comprises the following steps: the imaging system acquires a contour image of the focusing ring, and acquires the position deviation of the focusing ring relative to the electrostatic chuck based on the contour image of the focusing ring; The alignment structure moves the focus ring based on the positional deviation, eliminating the positional deviation.
9. The inspection method of claim 8, wherein the positional deviations comprise a first positional deviation of a center position of the focus ring and a center position of the electrostatic chuck on a first plane and a second positional deviation of the center position of the focus ring and the center position of the electrostatic chuck on a second plane, the first plane being perpendicular to a mounting plane of the electrostatic chuck and the second plane being parallel to the mounting plane of the electrostatic chuck, the first plane and the second plane being perpendicular, the imaging system comprising N imaging modules circumferentially arranged around the base, N being ∈3, the imaging modules comprising a first imaging module and a second imaging module, the first imaging module being opposite a side of the focus ring and the second imaging module being opposite a bottom of the focus ring, the imaging system acquiring a profile image of the focus ring and acquiring a positional deviation of the focus ring relative to the electrostatic chuck based on the profile image of the focus ring comprising: the first imaging module acquires a side profile image of the focusing ring and acquires the first position deviation based on the side profile image of the focusing ring; The second imaging module acquires a bottom profile image of the focus ring and acquires the second positional deviation based on the bottom profile image of the focus ring.
10. The method of claim 9, wherein the first imaging module includes a first lens group, a first image sensing unit, a first image processing unit, and a first signal transmission unit that stores the first positional deviation and transmits the first positional deviation to the calibration structure, wherein the first imaging module acquiring a side profile image of the focus ring and acquiring the first positional deviation based on the side profile image of the focus ring comprises: The first image sensing unit converts the first optical signal into a first electric signal and transmits the first electric signal to the first image processing unit, and the first image processing unit acquires the first position deviation based on the first electric signal; the second imaging module comprises a second lens group, a second image sensing unit, a second image processing unit and a second signal transmission unit, wherein the second signal transmission unit stores the second position deviation and transmits the second position deviation to the calibration structure, and the second imaging module acquires the bottom contour image of the focusing ring and acquires the second position deviation based on the bottom contour image of the focusing ring, and the second imaging module comprises: The second lens group acquires a second optical signal, and transmits the second optical signal to the second image sensing unit, wherein the second optical signal carries the bottom contour information of the focusing ring, the second image sensing unit converts the second optical signal into a second electric signal and transmits the second electric signal to the second image processing unit, and the second image processing unit acquires the second position deviation based on the second electric signal.
11. The detection method according to claim 10, wherein the first image processing unit acquiring the first positional deviation based on the first electric signal includes: A first image processing unit in the N imaging modules acquires N imaging heights of the focusing ring based on the first electric signals obtained by the first image processing units; acquiring the first position deviation based on the difference values of the N imaging heights; the second image processing unit acquiring the second positional deviation based on the second electric signal includes: a second image processing unit in the N imaging modules acquires N gap values between the focusing ring and the cover ring based on the second electric signals obtained by the second image processing units; And acquiring the second position deviation based on the N gap values.
12. The method of detecting according to claim 11, further comprising: comparing the imaging height of the focusing ring with the reference height of the focusing ring to obtain the height deviation of the focusing ring; wherein the reference height of the focus ring is the initial height of the focus ring.

Description

Etching equipment with imaging system and detection method Technical Field The application relates to the technical field of semiconductor etching, in particular to etching equipment with an imaging system and a detection method. Background With the development of semiconductor devices in smaller size and higher precision, the requirements of wafer processing on dry etching technology, equipment and the like are increasing. 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 positional accuracy of the focus ring, such as the centering and leveling of the focus ring, will directly affect the wafer etch uniformity and etch rate. Poor accuracy can affect the electric field and sheath distribution over the electrostatic chuck, which can lead to uneven plasma distribution over the wafer, particularly near the focus ring, affecting etch rate and uniformity at the wafer edge. Disclosure of Invention In view of the above, the present application provides an etching apparatus and a detection method with an imaging system, and the scheme is as follows: An etching apparatus having an imaging system, comprising: the etching structure is used for realizing the etching of the workpiece 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 imaging system is positioned on the cover ring and is used for acquiring a contour image of the focusing ring and acquiring the position deviation of the focusing ring relative to the electrostatic chuck based on the contour image of the focusing ring; And a calibration structure that moves the focus ring based on the positional deviation, eliminating the positional deviation. Optionally, the positional deviation includes a first positional deviation and a second positional deviation; The first position deviation is the deviation of the central position of the focusing ring and the central position of the electrostatic chuck on a first plane, the second position deviation is the deviation of the central position of the focusing ring and the central position of the electrostatic chuck on a second plane, the first plane is perpendicular to the mounting plane of the electrostatic chuck, the second plane is parallel to the mounting plane of the electrostatic chuck, and the first plane and the second plane are perpendicular; The imaging system comprises N imaging modules which are circumferentially distributed around the base, wherein N is more than or equal to 3, each imaging module comprises a first imaging module and a second imaging module, the first imaging module is opposite to the side part of the focusing ring and is used for acquiring a side contour image of the focusing ring and acquiring the first position deviation based on the side contour image of the focusing ring, and the second imaging module is opposite to the bottom of the focusing ring and is used for acquiring a bottom contour image of the focusing ring and acquiring the second position deviation based on the bottom contour image of the focusing ring. The first imaging module comprises a first lens group, a first image sensing unit, a first image processing unit and a first signal transmission unit, wherein the first lens group acquires a first optical signal and transmits the first optical signal to the first image sensing unit, the first optical signal carries side profile information of the focusing ring, the first image sensing unit converts the first optical signal into a first electric signal and transmits the first electric signal to the first image processing unit, and the first image processing unit acquires the first position deviation based on the first electric signal; The second imaging module comprises a second lens group, a second image sensing unit, a second image processing unit and a second signal transmission unit, wherein the second lens group acquires a second optical signal and transmits the second optical signal to the second image sensing unit, the second optical signal carries the bottom profile information of the focusing ring, the second image sensing unit converts the second optical signal into a second electric signal and transmits the second electric signal to the second image processing unit, and the second image processing unit acquires the second position deviation based on the second electric signal; the first signal transmission unit also provides electric energy for each component in the first imaging module, and the second signal transmission unit also provides electric energy for each component i