Rotating Mask Substrate Cleaning Apparatus Prevents Recontamination
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Solution Overview
Problem
Current dry cleaning methods using laser shock waves for semiconductor substrates face issues with substrate recontamination due to plumes or residence beams damaging the mask and contaminating the substrate, as the mask is fixed and only rotates with the focal point, leading to continuous exposure to these beams.
Innovation Solution
A substrate cleaning apparatus with a rotating mask that periodically switches the shielding region adjacent to the focal point, preventing the concentration of plumes or residence beams on a specific portion of the mask, thereby reducing damage and recontamination, and includes a supporting plate, beam generator, lens, and shielding unit to manage shock waves and foreign substance removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a fixed mask is used to protect the substrate from plumes and residence beams, then substrate protection is improved, but the mask is continuously exposed to these beams causing mask damage and recontamination
Solution Approach 1:
The mask is changed from a fixed structure to a rotating structure that periodically switches the shielding region adjacent to the focal point. This dynamic configuration allows different portions of the mask to be exposed to plumes and residence beams alternately, preventing continuous exposure and damage to a single mask region while maintaining substrate protection.
Solution Approach 2:
The mask rotation implements periodic action by cyclically switching the shielding region. This periodic movement ensures that no single portion of the mask is continuously exposed to harmful plumes and residence beams, thereby reducing mask damage and preventing recontamination of the substrate while maintaining continuous protection.
2Productivity
If laser shock waves are focused above the substrate to remove foreign substances, then cleaning effectiveness is improved, but plumes and residence beams are generated that can damage the mask and contaminate the substrate
Solution Approach 1:
The rotating mask dynamically changes the shielding region adjacent to the focal point during the cleaning process. This dynamic adjustment allows the system to maintain effective laser focusing for cleaning while distributing the exposure to harmful plumes and residence beams across different mask portions, preventing mask damage and substrate recontamination.
Solution Approach 2:
The rotating mask acts as an intermediary between the laser focal point and the substrate. By periodically switching the shielding region, it mediates the interaction between plumes/residence beams and the mask-substrate system, allowing cleaning to proceed effectively while preventing direct continuous exposure that would cause damage and recontamination.
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 solution effectively prevents mask damage and substrate recontamination by dispersing the concentration of plumes or residence beams, enhancing cleaning efficiency and maintaining substrate cleanliness.
Implementation Method 1
The beam generator emits light for generating shock waves cleaning the substrate
Implementation Method 2
focusing light at a point adjacent the mask to generate shock waves above the substrate
Data Source
AI summary
A substrate cleaning apparatus includes a supporting plate supporting a substrate and a shielding unit that is disposed above the substrate to protect the substrate. A portion of the shielding unit, which is adjacent to a focal point where light for generating shock waves is focused, is switched. Therefore, the substrate cleaning apparatus prevents the concentration of plumes and residence beams, which are generated together with the shock waves, on a specific region of the shielding unit and further prevents the recontamination of the substrate by the damage of the shielding unit.