Semiconductor Alignment Key via Device Isolation Film
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Solution Overview
Problem
The conventional method for manufacturing semiconductor devices involves an additional key open process that increases the total around time (TAT) and manufacturing cost due to the need for extra steps such as key open photo, etching, resist removal, and cleaning processes.
Innovation Solution
A method where a first alignment key is formed during the device isolation film process on a scribe lane, and a second alignment key is used during the recess gate region formation, skipping the key open process to reduce process steps and costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a key open process is performed to form a deeper alignment key using photoresist etching, then alignment precision is improved, but manufacturing time and cost increase due to additional process steps
Solution Approach 1:
The device isolation film formation process is performed in advance on the scribe lane to create a step difference that serves as an alignment key. This preliminary action eliminates the need for subsequent key open processes, reducing manufacturing time while maintaining alignment precision for the recess gate formation.
Solution Approach 2:
The device isolation film formation process serves multiple functions: it creates the device isolation structure in the cell region and simultaneously forms an alignment key in the scribe lane. This multi-functionality eliminates the need for separate key open processes, reducing both time and cost.
2Manufacturing precision
If a key open process is performed to form a deeper alignment key using photoresist etching, then alignment precision is improved, but manufacturing cost increases due to additional process steps
Solution Approach 1:
The device isolation film formation process serves multiple functions: it creates the device isolation structure in the cell region and simultaneously forms an alignment key in the scribe lane. This multi-functionality eliminates the need for separate key open processes, reducing both time and cost.
Solution Approach 2:
The alignment key formation is merged with the device isolation film formation process. By combining these two functions into a single process step, the manufacturing cost is reduced while maintaining the necessary alignment precision for subsequent gate formation.
3Reliability
If the device isolation film is formed only on the cell region, then device isolation performance is improved, but alignment key formation requires separate processes increasing complexity
Solution Approach 1:
The device isolation film is formed with different characteristics in different regions: in the cell region it provides device isolation, while in the scribe lane it creates a step difference that serves as an alignment key. This local differentiation allows the same process to serve multiple functions without compromising device isolation performance.
Data Source
AI summary
Disclosed herein is a method for manufacturing a semiconductor device. According to the present invention, a device isolation film having a step difference occurring during a process of forming a device isolation film in a scribe lane region serves as a first alignment key, and a second alignment key formed during a process of forming a recess gate region is used in the subsequent process, thereby improving the process steps and product cost.