Adaptive beam current for high throughput patterning

Patent metadata

Field	Value
Publication number	US-10415133-B2
Application number	US-201615199690-A
Country	US
Kind code	B2
Filing date	Jun 30, 2016
Priority date	Jul 2, 2015
Publication date	Sep 17, 2019
Grant date	Sep 17, 2019

Abstract

A method for planning a beam path for material deposition is provided in which a structure pattern having features of varying size is analyzed to determine the size of each feature. A beam path throughout the structure pattern is determined and the beam current required for each point in the structure pattern is configured. Configuring the beam current required for each point involves determining the acceptable beam dose for that point. Relatively small features require a low beam current for high accuracy and relatively large features can be formed using a higher beam current allowing faster deposition. Each feature in the structure pattern is deposited at the highest beam current acceptable to allow accurate deposition of the feature.

First claim

I claim as follows:

1. A method of beam-induced material deposition, comprising:
creating a map specifying two-dimensional features to be deposited on a surface by a charged particle beam having a beam current that can be varied, the two-dimensional features including a first feature and a second feature having different sizes;
analyzing the map to determine the sizes of the first and second features;
using the size of the first feature to determine a first beam current at which to deposit the first feature, and the size of the second feature to determine a second beam current at which to deposit the second feature, the second beam current being different than the first beam current, wherein the first beam current and second beam current are each chosen based a current requirement of a group of dwell points and not based on a current requirement of an individual dwell point;
depositing the two-dimensional features by scanning the charged particle beam over the surface according to a scan pattern, the scan pattern grouping wherein the beam deposits the first feature by scanning a first region of the surface at the first beam current, and the second feature by scanning a second region of the surface at the second beam current;
wherein the beam current is varied between the first beam current and the second beam current within a single scan of the scan pattern.

2. The method of claim 1 , further comprising changing the current of the charged particle beam from the first beam current to the second beam current by changing a size of a beam-defining aperture in a path of the charged particle beam to the surface.

3. The method of claim 2 , wherein scanning the first region comprises scanning different points in the first region at different dwell times.

4. The method of claim 1 , further comprising:
providing a description of a three-dimensional structure; and
dividing the three-dimensional structure into multiple two-dimensional layers,
wherein the map specifying the two-dimensional features is a map of one of the two-dimensional layers.

5. The method of claim 1 , further comprising:
providing a description of a three-dimensional structure to be deposited on the surface;
creating bitmaps of different planar layers of the three-dimensional structure, which taken together represent the three-dimensional structure, wherein the map of the two-dimensional features is a bitmap of one of the planar layers; and
forming the three-dimensional structure by performing the steps of claim 1 for each bitmap.

6. The method of claim 1 , wherein the charged particle beam deposits several of the features while at the first beam current and then deposits several of the features while at the second beam current.

7. A method of beam-induced material processing, comprising:
providing a structure pattern having features of varying sizes;
analyzing the structure pattern to determine the size of the features in the structure pattern,
determining a beam path to deposit the structure pattern;
determining a beam current required for each point in the structure pattern, wherein the beam currents required by at least two of the points in the structure pattern are different;
determining which points in the structure pattern have a similar required beam current;
scanning the beam along the beam path for a first group of points having a similar required beam current using the determined beam current at each of the first group of points in the structure pattern;
switching the beam current and scanning the beam along the beam path for a second group of points have a similar required beam current, wherein switching between the different beam currents determined for different points in the structure pattern is carried out by changing a size of a beam-defining aperture through which the beam passes while scanning the beam along the beam path; and
wherein the beam current is switched between the different beam currents within a single scan of the structure pattern.

8. The method of claim 7 , wherein the beam current varies at different points in the structure pattern according to the size of the feature containing the point.

9. The method of claim 7 , wherein the beam-induced material processing comprises material deposition.

10. The method of claim 9 , wherein the structure pattern comprises multiple planar layers, each of which will be deposited in a single scan of the beam.

11. The method of claim 10 , wherein the beam current varies during a single scan of the beam path.

12. A method of processing a work piece with a beam, comprising:
providing a bitmap to be patterned on the work piece using the beam, the bitmap corresponding to a planar layer of a structure pattern;
analyzing the bitmap to create a beam current bitmap that specifies a beam current at which to pattern each pixel of the bitmap onto the work piece;
analyzing said beam current bitmap to determine regions on the work piece to be processed by the beam with similar beam current, each region comprising a plurality of dwell points;
planning a single path on the work piece for the beam to scan that will pattern the planar layer on the work piece using at least two different beam currents; and
directing the beam along the path at the selected beam currents for each region to process the work piece, at least two different beam currents being used at different points along the path to process the work piece, wherein one region is processed before the beam current is changed for processing another region.

13. The method of claim 12 , further comprising switching between the at least two different beam currents by changing a size of a beam-defining aperture through which the beam passes when processing the work piece.

14. The method of claim 12 , in which directing the beam along the planned path comprises using different dwell times to process different points along the path.

15. The method of claim 12 , in which the bitmap is a first bitmap and the structure pattern is a description of a three-dimensional structure to be patterned on the work piece, further comprising:
creating additional multiple bitmaps, each bitmap corresponding to a different planar layer of the structure pattern, which taken together with the first bitmap represent the three-dimensional structure.

16. The method of claim 15 , further comprising, for each of the additional bitmaps:
analyzing the additional bitmap to create an additional beam current bitmap that specifies, for each pixel of the additional bitmap, a beam current at which to process the position on the work piece corresponding to the pixel when patterning the planar layer of the additional bitmap;
analyzing said additional beam current bitmap to determine regions on the work piece to be processed with similar beam current;
planning a beam path for processing the work piece that will pattern the planar layer of the additional bitmap on the work piece; and
directing the beam along the beam path planned for patterning the planar layer of the additional bitmap at the selected beam currents to process the work piece, at least two different beam currents being used in the planned beam path for processing the work piece, and changing from one beam current to another being carried out by changing a size of a beam-defining aperture through which the beam passes when processing the work piece.

Assignees

• Fei Co

Inventors

• Botman Aurelien Philippe Jean Maclou

Classifications

• H01J2237/31732

  Depositing thin layers on selected microareas · CPC title

• C23C16/486

  using ion beam radiation · CPC title

• C23C16/047

  using irradiation by energy or particles · CPC title

• C23C14/30

  by electron bombardment · CPC title

• C23C14/221 Primary

  Ion beam deposition (C23C14/46, C23C14/48 take precedence) · CPC title