Semiconductor Wafer Developing Method with Pre-wet Liquid
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Solution Overview
Problem
Existing developing methods for semiconductor substrates face challenges in achieving high in-plane uniformity and reducing defects due to re-adhesion of components, especially when dealing with highly water-repellent surfaces, which can lead to increased processing time and liquid consumption.
Innovation Solution
A developing method where a substrate coated with resist is rotated horizontally and simultaneously supplied with a developing liquid and a rinse liquid from nozzles moving from the center to the periphery, with a gas jetting step to enhance surface wetting and rinsing, ensuring uniform coverage and efficient processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a developing liquid is supplied onto a wafer having a water-repellent resist film, then the developing process can proceed, but the liquid is repelled by the surface resulting in non-uniform coverage and increased processing time
Solution Approach 1:
A pre-wet liquid is supplied onto the wafer surface before the developing liquid to modify the surface properties. This preliminary action reduces the water-repellency of the resist film, enabling subsequent uniform coverage by the developing liquid and reducing processing time while maintaining CD uniformity.
Solution Approach 2:
The pre-wet liquid acts as an intermediary substance between the water-repellent resist film and the developing liquid. It temporarily modifies the surface energy of the resist, allowing the developing liquid to spread uniformly without being repelled, thus resolving the contradiction between uniformity and processing time.
2Manufacturing precision
If a large amount of developing liquid is supplied to cover the whole wafer surface, then uniform development is achieved, but liquid consumption increases
Solution Approach 1:
The pre-wet liquid is supplied in a controlled amount before the developing liquid to prepare the surface. This preliminary conditioning allows the subsequent developing liquid to spread more efficiently and uniformly across the wafer surface, achieving uniform development with reduced overall liquid consumption.
Solution Approach 2:
The surface energy parameters of the resist film are temporarily changed by the pre-wet liquid, altering its wettability. This parameter change enables the developing liquid to achieve uniform coverage with a smaller volume, reducing liquid consumption while maintaining development uniformity.
3Productivity
If the wafer is rotated at high speed to improve liquid distribution, then processing efficiency increases, but centrifugal force causes liquid to spread radially and dissolve components are removed, affecting process margin
Solution Approach 1:
The pre-wet liquid is supplied before the developing liquid during wafer rotation. This preliminary action ensures that the resist film surface is properly conditioned before the developing liquid is applied, allowing for controlled dissolution and development while managing the effects of centrifugal force to maintain process margin.
Solution Approach 2:
The developing process is performed continuously during wafer rotation without interruption. The pre-wet liquid and developing liquid are supplied in a continuous manner, maintaining steady-state conditions that balance centrifugal effects with liquid distribution, thereby preserving process margin while achieving high productivity.
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 method achieves high in-plane uniformity, reduces defects, and shortens processing time while effectively managing water-repellent surfaces, thereby improving process efficiency and reducing liquid consumption.
Implementation Method 1
a pre-wet liquid which is different from the developing liquid is supplied onto a wafer before the developing liquid is supplied onto the wafer
Implementation Method 2
the wafer is rotated about a vertical axis... moves a developing nozzle from the center toward the periphery of the wafer while the developing nozzle supplies a strip-shaped developing liquid
Data Source
AI summary
A method of developing a substrate including rotating the substrate and supplying a developing liquid from a discharge port of a developer nozzle onto the surface of the substrate, while moving the developer nozzle, disposed above the substrate, from a central portion towards a peripheral portion of the substrate, and supplying a first rinse liquid from a discharge port of a first rinse nozzle onto the surface of the substrate, while moving the first rinse nozzle, disposed above the substrate, from the central portion towards the peripheral portion of the substrate. The supplying of the developing liquid and the first rinse liquid are performed concurrently, with the first rinse nozzle being maintained nearer to a center of the substrate than the developer nozzle.