Spin Coating Film Deposition for Substrate Through-Hole Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In three-dimensional device manufacturing, particularly for semiconductor integrated circuits, MEMS, and quantum computers, the presence of through-holes on substrates leads to deterioration in film thickness uniformity of resist films during lithography, causing pattern dimensional accuracy issues. Additionally, forming through-hole vias for quantum computers is challenging due to potential damage from plasma treatments and difficulties in achieving sufficient film thickness uniformity.
Innovation Solution
A film deposition method involving a spin coating process where a substrate with through-holes is coated with a first liquid having viscosity, which is held until it reaches the top surface through the holes, then rotated and heated to form a uniform thin film. This method includes using a second liquid as a solvent to improve affinity and spread the first liquid uniformly, and optionally applying a third liquid to further enhance film thickness uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a through-hole is formed on a substrate, then ground patterns can be connected between front and back surfaces to suppress microwave noise, but film thickness uniformity deteriorates due to the presence of the through-hole
Solution Approach 1:
The through-hole is filled with a first liquid having viscosity before the spin coating process. This preliminary action ensures that the through-hole does not interfere with the subsequent resist film formation, as the viscous liquid prevents resist from entering the through-hole during the coating process.
Solution Approach 2:
A first liquid having viscosity is introduced as an intermediary substance to block the through-hole from affecting film uniformity. This intermediary liquid prevents direct contact between the resist film and the through-hole, thereby maintaining manufacturing precision while allowing the through-hole to remain open for its grounding function.
2Ease of manufacture
If plasma treatment is performed to form a through-hole via, then through-substrate vias can be created for ground pattern connection, but the superconducting circuit particularly the Josephson junction part may be damaged
Solution Approach 1:
The patent replaces the plasma-based mechanical/chemical etching method with a liquid-filled approach. Instead of using plasma to physically remove material through the substrate, a viscous liquid is used to block and redirect the coating process, thereby forming through-holes without damaging the superconducting circuits.
Solution Approach 2:
The patent converts the harmful effect of the through-hole (which normally causes film thickness variation) into a beneficial blocking mechanism. By filling the through-hole with a viscous liquid, the hole that would normally disrupt film uniformity instead acts as a barrier that prevents resist from entering, thereby protecting the superconducting circuit while still allowing the through-hole to serve its grounding function.
3Ease of operation
If the substrate is rotated during spin coating, then centrifugal force causes resist to move from center to periphery, but gravity causes resist to enter the through-hole reducing supply amount to outer periphery
Solution Approach 1:
The first liquid having viscosity serves as an intermediary that blocks the through-hole from the centrifugal force-driven resist flow. This intermediary liquid prevents resist from being pulled into the through-hole by gravity during rotation, thereby maintaining uniform resist supply to the outer periphery.
Solution Approach 2:
The patent changes the physical state of the blocking material from solid (traditional through-hole closure) to liquid with specific viscosity properties. This parameter change allows the blocking material to remain fluid during the spin coating process, preventing resist infiltration while maintaining the through-hole structure for later use.
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 method achieves improved film thickness uniformity on substrates with through-holes, reducing manufacturing variations and maintaining the integrity of sensitive device components like Josephson junctions in quantum computers.
Implementation Method 1
adding a first liquid having viscosity dropwise onto a second main surface of the substrate... until the first liquid added dropwise reaches the first main surface side from the second main surface side through the through-hole
Implementation Method 2
rotating the substrate together with the turntable... the resist moves from the rotation center side towards the substrate outer periphery by centrifugal force
Implementation Method 3
heating the first liquid together with the substrate... heating the first liquid having viscosity together with the substrate
Data Source
AI summary
A film deposition method including installing a substrate on a turntable of a spin coating device such that a first main surface faces the turntable, and adding a first liquid having viscosity dropwise onto a second main surface of the substrate; holding the substrate in the same state until the first liquid added dropwise reaches the first main surface side from the second main surface side through a through-hole; otating the substrate together with the turntable; and heating the first liquid together with the substrate.