Focused Particle Beam Repair With Sacrificial Drift Marks
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Solution Overview
Problem
In microelectronics, photolithographic masks and templates often have defects that are difficult to repair accurately due to thermal and mechanical drifts, and existing reference marks used for drift correction are prone to changes during processing, leading to reduced accuracy and potential electrostatic charging issues during particle beam-induced repair processes.
Innovation Solution
A method involving the use of a sacrificial layer, which can be electrically conductive, is introduced to correct beam drift and prevent electrostatic charging, allowing for precise drift correction and defect repair without altering the reference marks' structure or leaving residue.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If reference marks are used for drift correction during particle beam repair, then beam positioning accuracy is improved, but electrostatic charging occurs and reference marks may change structure during processing
Solution Approach 1:
A conductive sacrificial layer is introduced as an intermediary between the particle beam and the reference mark. This sacrificial layer absorbs the electrostatic charging effects and beam-induced modifications, allowing the reference mark to remain structurally stable while still enabling drift correction. The sacrificial layer acts as a buffer that protects the reference mark from direct interaction with the particle beam's harmful effects.
Solution Approach 2:
The conductive sacrificial layer is designed to be temporary and disposable. It is deposited before repair, serves its protective function during the repair process, and then removed afterward. This sacrificial element absorbs the damage and charging effects that would otherwise affect the permanent reference mark, allowing the reference mark to maintain its functionality throughout multiple repair operations.
2Ease of repair
If particle beam is used for local etching and deposition to repair defects, then defect correction capability is improved, but thermal and mechanical drifts cause position shifts reducing repair accuracy
Solution Approach 1:
The system employs continuous feedback through reference marks that are scanned at regular intervals during the repair process. The position of the reference mark is monitored, and any drift detected is used to correct the beam position in real-time. This closed-loop feedback mechanism compensates for thermal and mechanical drifts, maintaining repair accuracy throughout the process.
Solution Approach 2:
The conductive sacrificial layer is deposited in advance before the actual repair operation. This preliminary action prepares the surface by providing a stable, conductive base that prevents electrostatic charging during subsequent particle beam processing, thereby ensuring better positioning accuracy from the outset of the repair operation.
3Device complexity
If conventional repair processes are used without sacrificial layer, then process simplicity is maintained, but electrostatic charging and reference mark degradation occur
Solution Approach 1:
The conductive sacrificial layer serves as a temporary intermediary that protects the reference mark during particle beam processing. It absorbs the electrostatic charging and beam-induced modifications, allowing the reference mark to maintain its structural integrity and functionality throughout the repair process.
Solution Approach 2:
The introduction of the sacrificial layer changes the electrical parameters of the processing surface by providing a conductive path that dissipates electrostatic charges. This parameter change prevents charge accumulation that would otherwise degrade the reference mark, while the layer itself is designed to be easily removed after serving its protective function.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The sacrificial layer enables improved precision in defect correction by maintaining reference mark functionality and preventing electrostatic distortions, resulting in higher quality repairs and reduced damage to the sample.
Implementation Method 1
particle beam-induced local etching processes and/or local deposition processes
Implementation Method 2
particle beam-induced local etching processes and/or local deposition processes
Implementation Method 3
correcting a drift of the focused particle beam in relation to the at least one defect during the repairing of the at least one defect
Data Source
AI summary
The present invention relates to a method for repairing at least one defect of a sample using a focused particle beam, comprising the steps of: (a) producing at least one first local, electrically conductive sacrificial layer on the sample, wherein the first local, electrically conductive sacrificial layer has a first portion and at least one second portion, wherein the first portion is adjacent to the at least one defect and wherein the first portion and the at least one second portion are electrically conductively connected to one another; and (b) producing at least one first reference mark on the at least one second portion of the first local, electrically conductive sacrificial layer for the purposes of correcting a drift of the focused particle beam in relation to the at least one defect while the at least one defect is being repaired.