Bump measurement height metrology

Patent metadata

Field	Value
Publication number	US-12474162-B2
Application number	US-202118005352-A
Country	US
Kind code	B2
Filing date	Jul 11, 2021
Priority date	Jul 13, 2020
Publication date	Nov 18, 2025
Grant date	Nov 18, 2025

Abstract

A method for measuring height differences between tops of multiple bumps of an upper surface of a layer, the method may include performing first measurements of the height differences between the bumps and the corresponding areas, by illuminating the bumps and the corresponding areas with first radiation; wherein the first measurements are subjected to first measurement errors; and determining the height differences between the bumps and the corresponding areas based on the first measurements and the first measurements errors.

First claim

I claim:

1 . A method for measuring height differences between tops of multiple bumps and corresponding areas of an upper surface of a layer, the method comprises:
performing first measurements of the height differences between the bumps and the corresponding areas, by illuminating the bumps and the corresponding areas with first radiation; wherein the first measurements are subjected to first measurement errors resulting from a virtual penetration of the first illumination into the layer; wherein each bump has a corresponding area that is proximate to the bump; preforming second measurements of height differences between a subgroup of the bumps and a subgroup of the corresponding areas, by illuminating the subgroup of the bumps and the subgroup of the corresponding areas with second radiation that does not penetrate the layer; wherein a duration of a second measurement exceeds a duration of a first measurement; determining first measurement errors, based on the first measurements and the second measurements; and determining the height differences between the bumps and the corresponding areas based on the first measurements and the first measurements errors.

2 . The method according to claim 1 wherein the bumps are spread along a round semiconductor substate, and wherein the subgroup of the bumps are positioned at spaced apart annual regions of the semiconductor substate wafer.

3 . The method according to claim 1 wherein the subgroup of the bumps comprise less than ten percent of the bumps.

4 . The method according to claim 1 wherein the first radiation is white light.

5 . The method according to claim 1 wherein the layer comprises at least one of Photo-definable polyimides and polybenzoxazoles.

6 . The method according to claim 1 wherein the determining of the height differences between the bumps and the corresponding areas comprises estimating the first measurements errors related to (a) bumps that do not belong to the subgroup of the bumps, and (b) corresponding areas that do not belong to the subgroup of corresponding areas.

7 . The method according to claim 6 wherein the estimating of the first measurements errors comprises extrapolation.

8 . The method according to claim 6 wherein the estimating of the first measurements errors comprises performing radial based extrapolation.

9 . The method according to claim 1 wherein the performing of the first measurements comprises performing white light triangulation.

10 . The method according to claim 1 wherein the performing of the second measurements comprises performing interferometry.

11 . A measurement system for measuring height differences between tops of multiple bumps and corresponding areas of an upper surface of a layer, the system comprises:
one or more measurement units and at least one processing unit that are configured to: perform first measurements of the height differences between the bumps and the corresponding areas, by illuminating the bumps and the corresponding areas with first radiation; wherein the first measurements are subjected to first measurement errors resulting from a virtual penetration of the first illumination into the layer; wherein each bump has a corresponding area that is proximate to the bump; preform second measurements of height differences between a subgroup of the bumps and a subgroup of the corresponding areas, by illuminating the subgroup of the bumps and the subgroup of the corresponding areas with second radiation that does not penetrate the layer; wherein a duration of a second measurement exceeds a duration of a first measurement; determine first measurement errors, based on the first measurements and the second measurements; and determine the height differences between the bumps and the corresponding areas based on the first measurements and the first measurements errors.

12 . The measurement system according to claim 11 wherein the bumps are spread along a round semiconductor substate, and wherein the subgroup of the bumps are positioned at spaced apart annual regions of the semiconductor substate wafer.

13 . The measurement system according to claim 11 wherein the subgroup of the bumps comprise less than ten percent of the bumps.

14 . The measurement system according to claim 11 wherein the first radiation is white light.

15 . The measurement system according to claim 11 wherein the layer comprises at least one of Photo-definable polyimides and polybenzoxazoles.

16 . The measurement system according to claim 11 wherein the measurement system is configured to determine height differences between the bumps and the corresponding areas by estimating the first measurements errors related to (a) bumps that do not belong to the subgroup of the bumps, and (b) corresponding areas that do not belong to the subgroup of corresponding areas.

17 . The measurement system according to claim 16 wherein the estimating of the first measurements errors comprises extrapolation.

18 . The measurement system according to claim 16 wherein the measurement system is configured to perform radial based extrapolation.

19 . The measurement system according to claim 11 wherein a first measurement unit is a white light triangulation unit.

20 . The measurement system according to claim 11 wherein a second measurement unit is an interferometer.

21 . A non-transitory computer readable medium for measuring height differences between tops of multiple bumps and corresponding areas of an upper surface of a layer, the non-transitory computer readable medium storing instructions for:
performing first measurements of the height differences between the bumps and the corresponding areas, by illuminating the bumps and the corresponding areas with first radiation; wherein the first measurements are subjected to first measurement errors resulting from a virtual penetration of the first illumination into the layer; wherein each bump has a corresponding area that is proximate to the bump; preforming second measurements of height differences between a subgroup of the bumps and a subgroup of the corresponding areas, by illuminating the subgroup of the bumps and the subgroup of the corresponding areas with second radiation that does not penetrate the layer; wherein a duration of a second measurement exceeds a duration of a first measurement; determining first measurement errors, based on the first measurements and the second measurements; and determining the height differences between the bumps and the corresponding areas based on the first measurements and the first measurements errors.

Assignees

• Camtek Ltd

Inventors

• Segev Eyal

Classifications

• G01B11/0616

  of coating · CPC title

• G01N21/956

  Inspecting patterns on the surface of objects {(contactless testing of electronic circuits G01R31/308; testing currency G07D; manufacturing processes per se of semiconductor devices implementing a measuring step H10P74/20)} · CPC title

• G01N21/9501

  Semiconductor wafers (manufacturing processes per se of semiconductor devices implementing a measuring step H10P74/20) · CPC title

• G01B11/06

  for measuring thickness {; e.g. of sheet material (thickness measurement by thermal means G01B21/085)} · CPC title

• G01B2210/56

  Measuring geometric parameters of semiconductor structures, e.g. profile, critical dimensions or trench depth · CPC title