Semiconductor Lift Ring Assembly for Centered, Tilt-Free Lift Pins
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Solution Overview
Problem
The existing lift pin assemblies in semiconductor processing chambers face challenges such as tilting, which leads to miscentering of substrates, premature lift pin failure due to scraping, and inadequate sealing, resulting in non-uniform gas flow and potential substrate damage.
Innovation Solution
A lift assembly with a ring-shaped body and movable blocks having flared openings and holes, allowing lift pins to be positioned without tilting and ensuring a secure fit, thereby preventing miscentering and premature failure, and maintaining a seal between the lift pins and substrate support.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If lift pins are tilted during operation to raise and lower the substrate, then the substrate can be transferred between positions, but the lift pins experience scraping against the substrate support openings leading to premature failure
Solution Approach 1:
The opening is divided into two distinct segments: an upper tapered portion and a lower cylindrical portion. The tapered portion accommodates the tilted lift pin during insertion, while the cylindrical portion provides a parallel, scrape-free fit once the pin is seated, thus separating the insertion function from the support function.
Solution Approach 2:
The tapered portion of the opening is designed to preliminarily guide and receive the tilted lift pin before the pin reaches the cylindrical portion. This preliminary action allows the pin to be inserted at an angle without causing scraping, as the taper absorbs the angular mismatch.
2Ease of operation
If lift pins are tilted during operation, then substrate transfer is enabled, but a gap forms between the lift pins and substrate support openings causing inadequate sealing
Solution Approach 1:
The opening is segmented into a tapered upper portion and a parallel lower portion. The parallel portion ensures complete contact between the lift pin and opening walls during the processing phase, eliminating gaps and preventing gas flow contamination while still allowing tilted insertion through the tapered section.
3Ease of operation
If lift pins are tilted during operation, then substrate transfer is possible, but the substrates become miscentered resulting in non-uniform gas flow
Solution Approach 1:
The opening is divided into a tapered portion for insertion and a parallel portion for precise positioning. The parallel portion acts as a reference that forces the lift pin (and attached substrate) into the correct centered position once inserted, separating the tilted insertion phase from the centered positioning phase.
Data Source
AI summary
Apparatuses and methods for loading and unloading substrates from a semiconductor manufacturing processing chamber are described. Some embodiments advantageously provide improved lift assemblies (e.g., lift ring designs) for centering lift pins in semiconductor processing chambers by allowing for unconstrained translation of the lift pins in the x-y plane. Some embodiments advantageously prevent lift pin tilting. Some embodiments advantageously provide a seal between the top end portion of the lift pins and the openings in the top surface. The lift assemblies include a ring-shaped body, a plurality of movable blocks configured to cooperatively interact with one or more openings of the ring-shaped body, and at least one ball bearing. The movable blocks include at least one indentation in a top surface of a bottom portion of the block and a complementary sized ball bearing in the at least one indentation.