Substrate Supporting Apparatus Gas Cushion Floating
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing substrate supporting apparatuses for semiconductor wafer processing face challenges in effectively cleaning the backside of wafers, as they often result in contamination of the front side due to metallic impurities diffusing through the substrate, and the gap height between the substrate and the apparatus is difficult to adjust, affecting cleaning efficiency and pattern integrity.
Innovation Solution
A substrate supporting apparatus featuring a rotatable chuck with adjustable gas flow-controlled injecting ports, locating pins, and guiding pillars to maintain a stable floating state of the substrate using the Bernoulli principle, preventing contact between the substrate's lower surface and the apparatus and ensuring precise positioning for effective backside cleaning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a projection is used to support the substrate during processing, then the substrate can be stably positioned, but the projection may cause the device side pattern broken and contamination
Solution Approach 1:
The patent introduces a gas cushion as an intermediary between the substrate and the support surface. Gas is supplied through injecting ports to create a floating state that mediates the contact between substrate and apparatus, preventing direct contact while maintaining stable positioning. This resolves the contradiction by eliminating harmful direct contact while preserving positioning stability.
Solution Approach 2:
The patent uses pneumatic principles by supplying gas through injecting ports to create a gas cushion that supports the substrate in a floating state. This pneumatic support system replaces mechanical projections, allowing stable positioning without pattern damage or contamination. The gas pressure and flow are controlled to maintain the substrate at the appropriate height.
2Ease of manufacture
If the gap height between the substrate and the apparatus is fixed, then the apparatus structure is simple, but the gap height is not easily adjustable affecting cleaning efficiency
Solution Approach 1:
The patent transforms the fixed gap structure into a dynamic, adjustable gap by incorporating gas flow control mechanisms. The mass flow controllers allow real-time adjustment of gas flow rates, enabling dynamic control of the substrate height and gap size. This maintains structural simplicity while enabling efficient cleaning operations through adjustable parameters.
Solution Approach 2:
The patent enables gap height adjustment by changing the gas flow parameters. Mass flow controllers modify the gas flow rate to the injecting ports, which changes the gas cushion pressure and consequently adjusts the substrate height. This parameter-based control allows flexible gap adjustment without complex mechanical structures.
3Object-affected harmful factors
If gas flow is increased to lift the substrate higher, then contamination is prevented, but the substrate stability decreases
Solution Approach 1:
The patent applies different gas flow characteristics to different regions through multiple injecting ports with different orientations. First injecting ports supply gas horizontally for suction and stable positioning, while second injecting ports supply gas vertically for lifting. This localized quality differentiation allows simultaneous achievement of contamination prevention and substrate stability.
Solution Approach 2:
The patent segments the gas supply system into multiple independent injecting ports with different functions. First injecting ports are dedicated to horizontal gas supply for suction and positioning stability, while second injecting ports handle vertical gas supply for lifting. This segmentation allows independent control of stability and contamination prevention functions.
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 apparatus maintains a stable floating state of the substrate, prevents contamination of the front side, and allows for adjustable gap height, enhancing the cleaning efficiency and quality of semiconductor devices by preventing direct contact and ensuring thorough cleaning of the backside.
Implementation Method 1
The nozzle is fed with compressed gas for the formation of a gas cushion between the apparatus and the substrate. The substrate is sucked above the apparatus by Bernoulli principle and keeps in a floating state.
Implementation Method 2
The second injecting ports are connected with a second gas passage for supplying gas to the substrate and lifting the substrate
Data Source
AI summary
A substrate supporting apparatus (300) for cleaning a back side of a substrate (107) is provided. The substrate supporting apparatus (300) has a hollow shaft (319) and a rotary spindle (303). The rotary spindle (303) is set in the hollow shaft (319) and a spacing is formed between an outer wall of the rotary spindle (303) and an inner wall of the hollow shaft (319). The outer wall of the rotary spindle (303) defines a blocking wall (322) and a recess (324) to prevent particles in the spacing from entering a gas groove (325) which is formed on the hollow shaft (319) and supplies gas to a front side of the substrate (107), avoiding the particles contaminating the front side of the substrate (107), which improves the quality of semiconductor devices.