Multi-Pass Trench Capacitor Fabrication Control
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Solution Overview
Problem
Current methods for controlling multi-pass processes in integrated circuit fabrication fail to account for substrate-to-substrate variations, leading to defective structures and devices due to broadened distribution of critical dimensions beyond allowable ranges.
Innovation Solution
The method involves obtaining both ex-situ and in-situ measurements of pre-etch and post-etch dimensions to adjust process recipes and control the operational status of etch and external substrate processing equipment, using a combination of external measuring tools and in-situ tools within the etch reactor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If ex-situ measurements are used to control multi-pass processes, then manufacturing simplicity is maintained, but substrate-to-substrate variations cause critical dimensions to broaden beyond allowable ranges
Solution Approach 1:
The patent combines ex-situ measurements with in-situ measurements into a unified control system. Ex-situ measurements provide baseline data, while in-situ measurements capture real-time variations during processing. The results from both measurement systems are integrated to adjust process recipes, achieving precise critical dimension control while accounting for substrate-to-substrate variations.
Solution Approach 2:
The patent performs ex-situ measurements before the multi-pass process to establish baseline critical dimensions, and in-situ measurements during the process to detect variations in real-time. This preliminary and continuous measurement approach allows proactive adjustment of process parameters to maintain critical dimensions within allowable ranges.
2Ease of operation
If statistical averaging of batch measurements is used, then process control is simplified, but substrate-to-substrate variations cannot be compensated
Solution Approach 1:
The patent performs ex-situ measurements on individual substrates before processing to establish baseline critical dimensions. This preliminary measurement allows each substrate to be characterized individually rather than relying on batch averaging, enabling subsequent process adjustments tailored to each substrate's specific dimensions.
Solution Approach 2:
The patent implements a feedback loop where in-situ measurements during the multi-pass process are compared against target critical dimensions. Based on this feedback, process recipes are dynamically adjusted for individual substrates to compensate for variations, maintaining precision without requiring complex manual intervention.
3Manufacturing precision
If process recipes are adjusted based on individual substrate measurements, then critical dimension precision is improved, but processing time and complexity increase
Solution Approach 1:
The patent performs ex-situ measurements on substrates before they enter the multi-pass process, establishing baseline critical dimensions in advance. This allows process recipes to be pre-adjusted for each substrate based on its specific dimensions, eliminating the need for time-consuming mid-process adjustments and reducing overall processing time.
Solution Approach 2:
The patent implements in-situ measurements that continuously monitor critical dimensions during the multi-pass process. This continuous monitoring allows real-time detection of deviations and immediate process adjustments, maintaining precision throughout the entire process without interrupting the workflow or requiring repeated measurement cycles.
Data Source
AI summary
A method for controlling a process for fabricating integrated devices on a substrate. The method includes ex-situ and in-situ measurements of pre-etch and post-etch dimensions for structures formed on the substrate and uses the results of the measurements to adjust process recipes and to control the operational status of etch and external substrate processing equipment. In one exemplary application, the method is used during a multi-pass process for fabricating a capacitive structure of a trench capacitor.