Charged Particle Beam Writing for Charge-Uniformized Patterning
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Solution Overview
Problem
Existing methods for correcting beam irradiation position shifts due to charging effects in semiconductor manufacturing, such as using antistatic films, are costly and unsuitable for chemically amplified resists, and result in increased correction residuals and variations with charge amount differences.
Innovation Solution
A charged particle beam writing method that irradiates both pattern and non-pattern regions with specific doses to uniformize the charge amount across the substrate, using a deflection system to adjust beam doses based on resist film charge amounts and pattern densities, thereby minimizing beam irradiation position variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If an antistatic film is formed on the substrate to prevent surface charging, then beam irradiation position shift is eliminated, but manufacturing cost increases due to new facilities needed and the film is incompatible with chemically amplified resists
Solution Approach 1:
The invention extracts and eliminates the need for antistatic films by implementing charging effect correction through software-based dose adjustment. The correction unit calculates and adjusts beam doses to compensate for charging effects, removing the harmful dependency on additional physical layers and facilities while maintaining beam position stability.
Solution Approach 2:
The invention changes the beam dose parameter dynamically based on pattern density and charging effects. By adjusting the beam dose according to calculated charging conditions, the system compensates for position shifts without requiring antistatic films, thus resolving the contradiction between precision and manufacturing simplicity.
2Ease of manufacture
If charging effect correction is performed without antistatic films, then manufacturing cost is reduced, but correction residual increases as charge amount difference between regions increases
Solution Approach 1:
The invention applies local quality by adjusting beam doses according to spatially varying pattern densities and charging conditions. The correction unit calculates specific dose adjustments for different regions based on their unique charging characteristics, thereby minimizing correction residuals while maintaining cost-effectiveness without antistatic films.
Solution Approach 2:
The system implements feedback by calculating charging effects based on pattern density and using this information to adjust subsequent beam doses. This closed-loop approach continuously compensates for charging effects, reducing correction residuals while avoiding the need for expensive antistatic film facilities.
3Manufacturing precision
If beam dose is increased to compensate for charging effects in high-density pattern regions, then beam irradiation position stability is improved, but resist film dissolution occurs in non-pattern regions
Solution Approach 1:
The invention applies local quality by implementing spatially selective dose adjustment. The correction unit calculates and applies different dose modifications specifically to pattern regions versus non-pattern regions, compensating for charging effects where needed while preventing resist dissolution in areas where patterns should not form.
Solution Approach 2:
The system applies partial action by selectively adjusting doses only in regions where charging effects occur, rather than uniformly increasing doses across the entire substrate. This targeted approach stabilizes beam position in pattern regions without causing harmful dissolution in non-pattern regions.
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
Reduces beam irradiation position variations by uniformly distributing charge amounts, enhancing precision and reducing correction residuals without the need for antistatic films, thus improving manufacturing efficiency and reducing costs.
Implementation Method 1
a charged particle beam is deflected by a deflector, and a pattern is written by irradiating, with the charged particle beam, a substrate having a resist film formed thereon
Data Source
AI summary
In a charged particle beam writing method according to an embodiment, a charged particle beam is deflected by a deflector, and a pattern is written by irradiating, with the charged particle beam, a substrate having a resist film formed thereon. The method includes irradiating a pattern region, in which a pattern is to be formed, with a beam at a first dose, irradiating at least part of a non-pattern region, in which a pattern is not to be formed, with the charged particle beam at a second dose, at which the resist film is not dissolved away, and determining the second dose based on the first dose and a charge amount of the resist film corresponding to a pattern density of the pattern region, wherein a charge amount difference between the pattern region and a non-dissolution irradiation region, which is irradiated at the second dose, is smaller than that obtained when the second dose is zero.