Search

CN-122015701-A - Double-layer scanning interferometry equipment and method for wafer full-sheet morphology measurement

CN122015701ACN 122015701 ACN122015701 ACN 122015701ACN-122015701-A

Abstract

The invention relates to a double-layer scanning interferometry device and a method for measuring the appearance of a whole wafer, wherein the double-layer scanning interferometry device and the method for measuring the appearance of the whole wafer comprise the steps of obtaining the size of the wafer to be detected and the local scanning range of a movable probe, dividing the wafer to be detected into a plurality of local areas which are adjacent to each other and have a preset overlapping amount according to the size of the wafer to be detected and the local scanning range, generating a scanning path of the movable probe according to each local area obtained by dividing, controlling a moving platform for carrying the wafer to be detected to move according to the scanning path so that the movable probe sequentially enters each local area, entering the next local area after the movable probe finishes scanning of the current local area until all the local areas finish scanning, and splicing the scanning data of each local area to generate a wafer whole-wafer appearance map.

Inventors

  • ZHENG SHAOYU

Assignees

  • 普雷赛斯(苏州)智能科技有限公司

Dates

Publication Date
20260512
Application Date
20260401

Claims (10)

  1. 1. A dual-layer scanning interferometry apparatus for wafer full-slice topography measurement, comprising: A mobile platform; The wafer carrier is arranged on the moving platform and used for carrying the wafer to be detected; The optical measuring device is arranged above the wafer carrier, a movable probe and a reference mirror are arranged in the optical measuring device, the reference mirror and a measuring light path of the movable probe form an interferometry reference together, and the movable probe is used for carrying out non-contact interferometry on the surface of the wafer to be detected; a controller connected to the mobile platform and the optical measurement device, respectively, the controller configured to: acquiring the size of a wafer to be detected and the local scanning range of a movable probe; Dividing the wafer to be detected into a plurality of local areas which are adjacent to each other and have a preset overlapping amount according to the size of the wafer to be detected and the local scanning range; Generating a scanning path of the movable probe according to each partial area obtained by dividing; controlling the mobile platform to move according to each divided partial area to enable the mobile probe to sequentially enter each partial area, and controlling the mobile probe to move according to the scanning path after the mobile probe finishes scanning of the current partial area, so that the mobile probe enters the next partial area until all the partial areas finish scanning; and splicing the scanning data of each local area to generate a wafer full-slice morphology graph.
  2. 2. The dual layer scanning interferometry apparatus for wafer full slice topography measurement of claim 1, wherein the controller is further configured to: controlling the moving platform to move according to each partial area obtained by dividing so as to enable the wafer to be detected to move to a preset position corresponding to the corresponding partial area; When the wafer to be detected moves to the preset position, the movable probe is controlled to complete scanning of a current local area according to the scanning path; and when the scanning is completed in the current partial area, controlling the mobile platform to move so that the movable probe enters the next partial area until all the partial areas are scanned.
  3. 3. The dual layer scanning interferometry apparatus for wafer full slice topography measurement of claim 1, wherein the controller is further configured to: when the movable probe finishes scanning of the current local area and the next local area is in the current local scanning range, controlling the movable probe to finish scanning of the current local scanning range; And when the movable probe finishes scanning of the current local area and the next local area exceeds the current local scanning range, controlling the movable platform to move so that the movable probe enters the next local area.
  4. 4. The dual layer scanning interferometry apparatus for wafer full slice topography measurement of claim 1, wherein the controller is further configured to: Acquiring positioning information corresponding to the mobile platform when the movable probe is in each local measurement and a coordinate system relative position relationship between the mobile platform and the movable probe calibrated in advance; according to the positioning information and the relative position relation of the coordinate system, converting the scanning data of each local area into the same global coordinate system; And splicing the scanning data converted into the same global coordinate system to generate a wafer full-slice morphology graph.
  5. 5. The dual-layer scanning interferometry apparatus for wafer full-slice topography measurement of claim 4, wherein stitching the scan data converted to the same global coordinate system to generate a wafer full-slice topography map comprises: Determining a space overlapping range between adjacent local areas according to a preset overlapping amount and global coordinates; fusing the two groups of scanning data in the determined spatial overlapping range; And splicing according to all the fused scanning data to generate a wafer full-slice morphology graph.
  6. 6. The dual-layer scanning interferometry apparatus for wafer full-slice topography measurement of claim 5, wherein after the step of fusing the two sets of scan data within the determined spatial overlap range, the step of stitching according to all the fused scan data to generate a wafer full-slice topography map further comprises: Calculating stitching errors of the two scanning data in the space overlapping range; After the step of splicing according to all the fused scanning data to generate the wafer full-slice morphology graph, the method further comprises the following steps: judging whether the stitching error exceeds a preset error threshold value or not to obtain a first judgment result; And when the first judgment result is yes, determining the local area corresponding to the scanning data as an abnormal area, and controlling the abnormal area to be measured again.
  7. 7. The dual layer scanning interferometry apparatus for wafer full slice topography measurement of claim 6, wherein the controller is further configured to: And when the difference value between the stitching error and the preset error threshold value is smaller than a first threshold value, controlling to increase the overlapping amount between the two local areas corresponding to the stitching error.
  8. 8. The dual layer scanning interferometry apparatus for wafer full slice topography measurement of claim 1, wherein a movable range of the movable probe corresponds to the local scanning range; And/or the number of the groups of groups, The movable probe performs point-wise movement by an encoder drive mechanism.
  9. 9. The dual-layer scanning interferometry apparatus for wafer full-slice topography measurement of claim 1, wherein the optical measurement device is a planar array infrared interferometry instrument.
  10. 10. A dual-layer scanning interferometry method for wafer full-slice topography measurement, comprising: acquiring the size of a wafer to be detected and the local scanning range of a movable probe; Dividing the wafer to be detected into a plurality of local areas which are adjacent to each other and have a preset overlapping amount according to the size of the wafer to be detected and the local scanning range; Controlling a mobile platform for bearing a wafer to be detected to move according to the scanning path so that the mobile probe sequentially enters each local area, and entering the next local area after the mobile probe finishes scanning of the current local area until all the local areas finish scanning; and splicing the scanning data of each local area to generate a wafer full-slice morphology graph.

Description

Double-layer scanning interferometry equipment and method for wafer full-sheet morphology measurement Technical Field The invention relates to the technical field of measurement, in particular to double-layer scanning interferometry equipment and method for measuring the appearance of a whole wafer. Background In the semiconductor manufacturing process, the surface morphology, flatness, warpage tendency and local fluctuation characteristics of the wafer directly affect the subsequent processes of photolithography, film deposition, bonding, packaging and the like, so that the wafer needs to be subjected to high-precision full-wafer morphology detection. Existing wafer topography detection devices typically use optical interferometry to obtain surface height information. Because of the limited single measurement field of view, when measuring an entire wafer, an external carrier is usually required to drive the wafer to move for multiple times relative to the measuring head so as to realize sequential measurement and subsequent splicing of multiple areas. For example, chinese patent document CN106292238a discloses a reflective off-axis digital holographic microscopic measuring device, which realizes three-dimensional morphological reconstruction of a sample through a beam splitter, a reference light path, an object light path, and a plurality of reflectors. The scheme can finish optical morphology measurement, but the technical key point is mainly light path construction and reference light path adjustment, and for a large-scale measurement scene facing the whole wafer, multi-area coverage still needs to be finished by an external platform or other relative movement mechanisms. As another example, chinese patent document CN112325765B discloses an optical microscopic measuring system that expands the measuring field of view by means of internal scanning, which can expand the measuring range under the conditions of a fixed working distance and higher spatial resolution. The scheme has a certain advantage in the aspect of expanding single measurement coverage, but the main focus is that the internal scanning expands the field of view, and no specific solution is provided for how to cooperate with an external XY platform, how to reduce the number of platform actions and how to establish a unified global coordinate system in the whole wafer measurement process. For another example, chinese patent document CN103217125A discloses a wafer surface topography measurement apparatus and a method thereof, and the scheme can realize wafer surface topography measurement, but still generally uses carrier movement to realize measurement coverage of different areas, and there is still a space for further optimization in terms of multi-size wafer switching, unified measurement reference maintenance and zone splicing efficiency. In the comprehensive view, the prior art respectively discloses schemes such as optical interferometry, internal scanning and expanding view field, wafer shape measuring equipment and the like, but in practical application, when the multi-area coverage is mainly carried out by depending on an external XY platform, the platform needs to be frequently started, stopped and transposed, after each movement, the platform needs to be stabilized, the whole measurement beat is easy to increase, the platform movement can introduce additional vibration to influence local measurement stability and stitching errors between adjacent areas, in a multi-size wafer switching scene, if a measurement reference depends on the posture of an external carrier or a sample, the calibration is often needed to be carried out again, so that the transformation efficiency is lower, and part of schemes also need to depend on the edge, a notch or an alignment mark of a wafer to establish a global coordinate system, so that the complexity of coordinate establishment and identification processing is increased. Therefore, it is still necessary to provide a new wafer full-wafer topography measurement apparatus, so as to reduce the number of actions of an external platform while ensuring the measurement coverage, shorten the measurement time, and maintain a uniform measurement reference when wafers of different sizes are switched. The foregoing is provided merely for the purpose of facilitating understanding of the technical solutions of the present invention and is not intended to represent an admission that the foregoing is prior art. Disclosure of Invention The invention mainly aims to provide double-layer scanning interferometry equipment and method for measuring the appearance of a whole wafer, and aims to solve the technical problems in the prior art. To achieve the above object, the present invention provides a dual-layer scanning interferometry apparatus for wafer full-slice topography measurement, comprising: A mobile platform; The wafer carrier is arranged on the moving platform and used for carrying the wafer to be detected; The op