Oblique Plasma Wafer Cleaning for Particle-Free Lithography
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Solution Overview
Problem
Existing methods for cleaning reticles and wafers in lithographic processes introduce particles and hydrocarbon contamination, leading to critical dimension non-uniformity and process delays, while solvent cleaning can introduce additional particles and prolong the process.
Innovation Solution
Utilizing a plasma generator to produce an oblique-angle plasma wind that disintegrates and removes particles and hydrocarbon contamination from reticles and wafers, maintaining vacuum conditions to prevent recontamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If solvent cleaning is used to clean reticles and wafers, then particles and hydrocarbon contamination are removed, but additional particles are introduced and process time is prolonged
Solution Approach 1:
The patent replaces solvent-based chemical cleaning with a mechanical/physical plasma cleaning system. The plasma generator creates ionized gas that physically removes particles and hydrocarbon contamination through ion bombardment and chemical reactions, eliminating the need for liquid solvents and subsequent drying steps, thus reducing process time while maintaining cleaning effectiveness
Solution Approach 2:
The patent changes the cleaning mechanism from liquid solvent application to plasma state gas treatment. By controlling plasma parameters (power, gas flow, pressure), the system achieves effective particle and hydrocarbon removal without introducing additional contamination, resolving the contradiction between cleaning quality and process efficiency
2Manufacturing precision
If solvent cleaning is used to clean reticles and wafers, then particles and hydrocarbon contamination are removed, but additional particles are introduced
Solution Approach 1:
The patent uses an inert plasma environment (typically nitrogen or oxygen plasma) to clean surfaces without introducing organic contamination. The plasma reacts with and removes hydrocarbons and particles while the inert nature of the plasma gas prevents introduction of additional contaminants, solving the particle introduction problem associated with solvent cleaning
Solution Approach 2:
By replacing liquid solvent cleaning with plasma cleaning, the system eliminates the source of additional particle contamination that comes from solvent application, evaporation, and handling. The plasma process leaves no residual particles while effectively removing existing contamination
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
Enhances critical dimension uniformity and reduces process delays by effectively cleaning surfaces without introducing new particles, ensuring efficient and precise lithographic processes.
Implementation Method 1
cleaning a particle from a surface of the semiconductor wafer in the treatment device by exposing the surface of the semiconductor wafer to a directional stream of plasma wind
Data Source
AI summary
In a method of manufacturing a semiconductor device a semiconductor wafer is retrieved from a load port. The semiconductor wafer is transferred to a treatment device. In the treatment device, the surface of the semiconductor wafer is exposed to a directional stream of plasma wind to clean a particle from the surface of the semiconductor wafer. The stream of plasma wind is generated by an ambient plasma generator and is directed at an oblique angle with respect to a perpendicular plane to the surface of the semiconductor wafer for a predetermined plasma exposure time. After the cleaning, a photo resist layer is disposed on the semiconductor wafer.