Tunable Diffuser for Uniform Curing in Semiconductor Planarization
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Solution Overview
Problem
Existing fluid deposition techniques in semiconductor fabrication face challenges with substrate planarization, particularly due to irregular substrate topography and defects caused by collimated light deflection by the superstrate chuck, which hinders uniform curing and feature placement in lithographic processes.
Innovation Solution
A method involving a tunable diffusing element that adjusts between collimated and diffused states to align and cure formable materials on substrates, using a system with a camera and lighting system for precise alignment and uniform energy distribution, comprising layers of materials like silicone, polyethylene terephthalate, and indium tin oxide to ensure consistent planarization and curing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If collimated light is used for curing the formable material, then the curing process can be efficient and direct, but the superstrate chuck deflects the collimated light causing non-uniform curing and defects
Solution Approach 1:
The patent transforms the light beam parameter from collimated to diffused by passing it through a diffuser element. This parameter change allows the light to maintain high energy for efficient curing while achieving uniform distribution across the substrate, eliminating the deflection issues caused by the superstrate chuck.
Solution Approach 2:
The diffuser element acts as an intermediary between the light source and the substrate. It receives the collimated light beams and transforms them into diffused beams, mediating the interaction to achieve both curing efficiency and uniformity without direct exposure of collimated light to the substrate through the chuck.
2Manufacturing precision
If a diffusing element is introduced to uniformize the light distribution, then curing uniformity improves, but the camera imaging resolution may deteriorate due to light diffusion
Solution Approach 1:
The system dynamically switches the diffusing element between two operational states: a first state during alignment when collimated beams pass through for high-resolution camera imaging, and a second state during curing when diffused beams provide uniform light distribution. This dynamic switching resolves the contradiction between imaging resolution and curing uniformity.
Solution Approach 2:
The diffusing element periodically transitions between collimated and diffused states according to the process requirements - collimated state for alignment and imaging, diffused state for curing. This periodic action allows both high-resolution imaging and uniform curing to be achieved at different times in the process sequence.
3Ease of manufacture
If the substrate surface has irregular topography, then subsequent layer deposition becomes difficult, but planarization requires additional processing steps
Solution Approach 1:
The patent performs planarization as a preliminary action before subsequent layer deposition. By dispensing and curing formable material to create a planarized surface early in the process, the system eliminates topography issues that would otherwise complicate future manufacturing steps, making overall manufacturing easier despite the added planarization step.
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
This approach enhances planarization by maintaining high camera imaging resolution and providing uniform curing, improving depth of focus, critical dimension control, and feature placement across the substrate, thereby addressing irregular topography and defects in semiconductor fabrication.
Implementation Method 1
tuning a diffusing element to a second operational state, where the first operational state is different from the second operational state, and curing the formable material over the substrate to form a layer over the substrate while the superstrate is contacting the formable material, where curing the formable material can include directing a set of actinic radiation beams to enter the diffusing element at an entering state and exit the diffusing element at an exiting state
Implementation Method 2
curing the formable material over the substrate to form a layer over the substrate while the superstrate is contacting the formable material
Data Source
AI summary
A method of forming a planarization layer on a substrate is disclosed. The method can include aligning a superstrate with the substrate, where aligning the superstrate with the substrate comprises tuning a diffusing element to a first operational state, dispensing a formable material over the substrate, contacting the formable material over the substrate with the superstrate, tuning the diffusing element to a second operational state, where the first operational state is different from the second operational state, and curing the formable material over the substrate to form a layer over the substrate while the superstrate is contacting the formable material, where curing the formable material can include directing a set of actinic radiation beams to enter the diffusing element at an entering state and exit the diffusing element at an exiting state, and where the entering state is different from the exiting state.