CN-117506687-B - Wafer carrier position detection device and method and polishing equipment

CN117506687BCN 117506687 BCN117506687 BCN 117506687BCN-117506687-B

Abstract

The invention provides a wafer carrier position detection device and method and polishing equipment, wherein the device comprises a plurality of positioning points, a plurality of positioning points and a polishing device, wherein the plurality of positioning points are distributed around the circumference of a target placement area at intervals so as to position the edge of a wafer carrier, and at least one positioning point is a laser positioning point; the device comprises a polishing pad, a laser sensor, a processor and a processor, wherein the laser sensor is arranged above the polishing pad, emits laser to a laser positioning point and receives a reflected laser signal returned from the laser positioning point, and the processor is in communication connection with the laser sensor and is used for comparing the reflected laser signal with a preset laser signal to judge whether a wafer carrier is positioned at a target position or not. According to the wafer carrier position detection device, the wafer carrier position detection method and the polishing equipment, the wafer carrier is accurately positioned, so that the phenomenon of product glazing is improved by avoiding a clean weak area caused by the blocking of the wafer carrier to a high-pressure cleaning water column.

Inventors

WANG BOLIANG

Assignees

西安奕斯伟材料科技股份有限公司
西安奕斯伟硅片技术有限公司

Dates

Publication Date: 20260505
Application Date: 20231218

Claims (11)

1. The wafer carrier position detection device is used in polishing equipment, the polishing equipment comprises a polishing pad, the polishing pad is provided with a plurality of placement areas, and the wafer carrier position detection device is used for placing the wafer carrier at a target position in the target placement areas, and is characterized in that the wafer carrier position detection device comprises: The positioning points are distributed around the circumference of the target placement area at intervals so as to position the edge of the wafer carrier, wherein at least one positioning point is a laser positioning point; A laser sensor disposed above the polishing pad, emitting laser light to the laser anchor point, and receiving reflected laser signals returned from the laser anchor point, and The processor is in communication connection with the laser sensor and is used for comparing the reflected laser signal with a preset laser signal to judge whether the wafer carrier is positioned at the target position or not; The laser positioning point is positioned on one side edge of the target placement area, which is close to the other placement area; The wafer carrier comprises a carrier body and teeth arranged on the periphery of the carrier body, tooth gaps are formed between adjacent teeth, the tooth gaps expose partial surfaces of the polishing pad, the carrier body, the teeth and the polishing pad are different in surface reflectivity, the preset laser signals at least comprise light intensity values of whether the wafer carrier is positioned at the target position or not, the laser is reflected by the surface of one of the tooth gaps and the teeth, and the processor is specifically used for comparing the light intensity values of the reflected laser signals with the light intensity values of the preset laser signals to judge whether the wafer carrier is positioned at the target position or not.
2. The wafer carrier position detection apparatus of claim 1, wherein there are three anchor points, one of the anchor points being the laser anchor point, and the other two anchor points being fixed mark points.
3. The wafer carrier position detection apparatus according to claim 2, wherein an inner pin ring and an outer pin ring are provided on the polishing pad, the placement area is located in a space between the inner pin ring and the outer pin ring, and one of the two fixed mark points is located at a position corresponding to a tangent point between the target placement area and the inner pin ring, and the other is located at a position corresponding to a tangent point between the target placement area and the outer pin ring.
4. The wafer carrier position detection apparatus of claim 1, wherein a surface reflectivity of the polishing pad is less than a surface reflectivity of the carrier body and the teeth, wherein the predetermined laser signal comprises a first light intensity value of the wafer carrier at the target position, the laser light being reflected back by the tooth gap surface, and wherein the processor is configured to: when the light intensity value of the reflected laser signal is equal to the first light intensity value, judging that the wafer carrier is currently positioned at the target position; And when the light intensity value of the reflected laser signal is larger than the first light intensity value, judging that the wafer carrier is not positioned at the target position currently.
5. The wafer carrier position detection apparatus of claim 4, wherein the predetermined laser signal further comprises a second intensity value at which the laser light is reflected back by the tooth surface, and wherein the processor is further configured to compare the intensity value of the reflected laser signal with the second intensity value to determine a current offset state of the wafer carrier.
6. The apparatus of claim 5, wherein the comparing the light intensity value of the reflected laser signal with the second light intensity value to determine the current offset state of the wafer carrier comprises: when the light intensity value of the reflected laser signal is equal to the second light intensity value, judging that the current offset state of the wafer carrier deviates from the target position in the circumferential direction of the wafer carrier; When the light intensity value of the reflected laser signal is smaller than the second light intensity value, the current offset state of the wafer carrier is judged to deviate from the target position in the radial direction of the wafer carrier, and the deviation direction is deviated away from the center of the placement area.
7. A polishing apparatus comprising the wafer carrier position detecting device according to any one of claims 1 to 6.
8. A wafer carrier position detection method, characterized in that a wafer carrier is placed on a target position of a target placement area in a polishing pad by using the wafer carrier position detection apparatus according to any one of claims 1 to 6, the method comprising the steps of: positioning the edge of the wafer carrier through a plurality of positioning points when the wafer carrier is placed, wherein Transmitting laser towards the laser positioning point through the laser sensor aiming at the laser positioning point, and receiving a reflected laser signal returned from the laser positioning point; And judging whether the wafer carrier is positioned on the target position or not based on the reflected laser signal and a preset laser signal.
9. The method of claim 8, wherein the predetermined laser signal comprises a first intensity value at the target position of the wafer carrier, the laser being reflected back by the standoff surface; The step of judging whether the wafer carrier is positioned on the target position based on the reflected laser signal and the preset laser signal specifically comprises the following steps: when the light intensity value of the reflected laser signal is equal to the first light intensity value, judging that the wafer carrier is currently positioned at the target position; And when the light intensity value of the reflected laser signal is larger than the first light intensity value, judging that the wafer carrier is not positioned at the target position currently.
10. The wafer carrier position detection method of claim 9, wherein the predetermined laser signal further comprises a second intensity value at which the laser light is reflected back by the tooth surface; The step of judging whether the wafer carrier is positioned on the target position based on the reflected laser signal and the preset laser signal specifically comprises the following steps: And comparing the light intensity value of the reflected laser signal with the second light intensity value to judge the current offset state of the wafer carrier.
11. The crystal according to claim 10a method for detecting the position of a circular carrier, it is characterized in that the method comprises the steps of, Comparing the light intensity value of the reflected laser signal with the second light intensity value to determine the current offset state of the wafer carrier, including: when the light intensity value of the reflected laser signal is equal to the second light intensity value, judging that the current offset state of the wafer carrier deviates from the target position in the circumferential direction of the wafer carrier; When the light intensity value of the reflected laser signal is smaller than the second light intensity value, the current offset state of the wafer carrier is judged to deviate from the target position in the radial direction of the wafer carrier, and the deviation direction is deviated away from the center of the placement area.

Description

Wafer carrier position detection device and method and polishing equipment Technical Field The invention relates to the technical field of semiconductor processing, in particular to a wafer carrier position detection device and method and polishing equipment. Background In the double-sided polishing process, silicate generated by the reaction of the polished wafer and the alkaline polishing solution is easy to generate in-solution enrichment accumulation due to instability of the chemical mechanical polishing process. If the cleaning ability after polishing is insufficient, the reaction products are extremely easy to generate saturated precipitation in the polishing pad, the grinding liquid pipeline and the storage tank, and white or yellow brown different precipitation is generated, namely, the equipment is glazed. The existence of the precipitated products brings inconvenience to daily maintenance and cleaning of equipment, and the heavy products are subjected to probabilistic shedding and gathering on the surface of a polishing pad in the material circulation, and periodically gathering to form glazed layers along with the movement of a wafer device carrier, so that uneven surface roughness distribution of the polishing pad is caused, and the glazed layers grind the products repeatedly, thereby generating product defects (defects) which mainly cause microscopic particle pollution or microscopic scratches. The glazing layer on the surface of the polishing pad can cause the surface of the polishing product to be printed or yellow, namely the glazing of the polishing product. Glazing phenomena of polished products can be classified into ring glazing, ribbon glazing and composite glazing. One reason for creating annular glazing is that the wafer carrier physically blocks the cleaning water column due to the positional displacement of the wafer carrier when placed due to factors such as human factors, thereby creating a glazing layer. In the related art, the method for solving the problem of annular glazing of the product is to trim the surface of the polishing pad to remove the glazing layer and restore the surface roughness of the polishing pad. However, as the surface of the polishing pad wears, the fixed conditioning conditions have not guaranteed that the polishing pad will maintain a stable removal rate throughout its lifetime. If a new polishing pad is replaced, this will result in increased costs. Disclosure of Invention The embodiment of the disclosure provides a wafer carrier position detection device, a wafer carrier position detection method and polishing equipment, which can prevent a clean weak area from being generated due to the blocking of a high-pressure cleaning water column by a wafer carrier by accurately positioning the wafer carrier so as to improve the glazing phenomenon of a product. The technical scheme provided by the embodiment of the disclosure is as follows: According to a first aspect of the present disclosure, there is provided a wafer carrier position detection apparatus for use in a polishing apparatus including a polishing pad provided with a plurality of placement areas, the wafer carrier position detection apparatus for placing the wafer carrier at a target position within the target placement areas, the wafer carrier position detection apparatus comprising: The positioning points are distributed around the circumference of the target placement area at intervals so as to position the edge of the wafer carrier, wherein at least one positioning point is a laser positioning point; A laser sensor disposed above the polishing pad, the laser sensor emitting laser light toward the laser anchor point and receiving reflected laser light signals returned from the laser anchor point, and And the processor is in communication connection with the laser sensors and is used for comparing the reflected laser signals with preset laser signals so as to judge whether the wafer carrier is positioned at the target position. Illustratively, there are three anchor points, one of the anchor points is the laser anchor point, and the other two anchor points are fixed mark points. Illustratively, the polishing pad is provided with an inner pin ring and an outer pin ring, the placement area is located in a space between the inner pin ring and the outer pin ring, one of the two fixed marking points is located at a position corresponding to a tangent point between the target placement area and the inner pin ring, the other fixed marking point is located at a position corresponding to a tangent point between the target placement area and the outer pin ring, and the laser positioning point is located at an edge of one side of the target placement area, which is close to the other placement area. The wafer carrier comprises a carrier body and teeth arranged on the periphery of the carrier body, tooth gaps are formed between adjacent teeth, the tooth gaps expose local surfaces of the polishing pad, the car