Semiconductor Wafer Processing System with Integrated Load Lock Cooling
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Solution Overview
Problem
Semiconductor wafer processing systems face challenges in achieving high throughput due to inefficient module arrangements and the need for separate cooling and heating stations, which increase processing time and costs.
Innovation Solution
A semiconductor wafer processing system with a loading station, load lock, intermediate process module, and transport module that includes a load chamber, transfer chamber, and pass-through chamber, allowing for fast pump down and vent cycles, wafer cooling during transit, and eliminating the need for separate cooling and heating stations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If separate cooling and heating stations are added to the system, then wafer temperature control capability is improved, but system complexity and processing time increase
Solution Approach 1:
The patent combines cooling and heating functions directly into the load lock chamber, eliminating the need for separate cooling and heating stations. The load lock is equipped with both a cooling system (including cooling plates and coolant circulation) and a heating system (including heating plates and temperature control), allowing temperature control to be integrated within the existing load lock structure rather than requiring additional dedicated stations.
Solution Approach 2:
The load lock chamber is designed to serve multiple functions: it not only performs vacuum pumping and wafer loading/unloading operations, but also provides both cooling and heating capabilities. This multi-functional design allows a single component (the load lock) to replace what would traditionally require multiple separate stations, reducing overall system complexity while maintaining comprehensive temperature control capability.
2Speed
If a single-wafer load lock with small volume is used, then pump down and vent cycle speed is improved, but wafer cooling capability may be compromised
Solution Approach 1:
The patent merges the cooling function directly into the single-wafer load lock chamber by installing cooling plates in contact with the wafer support pedestal. This integration ensures that even though the load lock has small volume for fast cycling, the wafer can still be effectively cooled during the vent cycle through direct thermal contact with the cooling plates, eliminating the need for a separate cooling station.
Solution Approach 2:
The cooling action is performed preliminarily during the vent cycle itself, rather than requiring a separate subsequent cooling step. The load lock cooling system begins cooling the wafer as soon as the chamber is vented, utilizing the venting time productively to reduce wafer temperature before the wafer is transferred to the process chamber or removed from the system.
3Productivity
If multiple process modules are arranged in a cluster tool, then processing capability is improved, but throughput is reduced due to inefficient module arrangement
Solution Approach 1:
The patent segments the cluster tool into distinct functional zones with dedicated transport paths. The system is divided into a load lock module, multiple process modules (PVD, CVD, etching), and a transport module with separate load chamber and transfer chamber. This segmentation allows each module to operate independently and efficiently, with optimized material flow paths that prevent bottlenecks and improve overall throughput.
Solution Approach 2:
The transport module acts as an intermediary between the load lock and process modules, featuring a dual-chamber design with a load chamber for receiving wafers from the load lock and a transfer chamber for distributing wafers to various process modules. This intermediary structure enables efficient wafer routing and reduces idle time by allowing parallel operations and minimizing transport distances between modules.
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
Improves throughput by reducing processing time and eliminating the need for additional stations, enhancing productivity and reducing costs by enabling continuous processing and efficient wafer handling within the system.
Implementation Method 1
The load lock is a single-wafer load lock capable of accommodating only a single wafer at a time, and correspondingly has a small volume which results in fast pump down and vent cycles
Implementation Method 2
the load lock is capable of cooling a wafer during a vent cycle
Implementation Method 3
the pass-through chamber is configured as a cooling station. For processes requiring the wafer to be cooled in-between depositions, the use of the pass-through chamber as a cooling station improves throughput by allowing the wafer to be cooled while it is in transit
Data Source
AI summary
A semiconductor wafer processing system in accordance with an embodiment of the present invention includes a loading station, a load lock, a process module, an intermediate process module, and a transport module which further includes a load chamber, a transfer chamber, and a pass-through chamber between the load chamber and the transfer chamber. The intermediate process module may be coupled to the load chamber, or both the load chamber and the transfer chamber. In one embodiment, the load lock is a single-wafer load lock capable of accommodating only a single wafer at a time to allow for fast pump down and vent cycles. In one embodiment, the pass-through chamber is configured as a cooling station to improve throughput for processes that require the wafer to be cooled in-between depositions, for example.