Semiconductor Contact Plug Alignment via Merged Well-Pickup
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Solution Overview
Problem
Conventional semiconductor devices face misalignment issues between drain contact plugs due to the enlargement of well-pickup contact plugs, leading to increased substrate and chip size, and higher complexity in fabrication processes.
Innovation Solution
The semiconductor device incorporates a well-pickup contact structure where contact plugs are formed with consistent spacing to prevent misalignment, using a method that involves forming isolation layers, contact holes, and conductive plugs to couple with active regions, thereby reducing the need for additional well-pickup contact plugs and minimizing substrate loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a well-pickup contact plug is formed between drain contact plugs according to conventional technology, then the well-pickup contact can be coupled with the substrate, but misalignment occurs between the series of drain contact plugs and the well-pickup contact plug
Solution Approach 1:
The patent merges the well-pickup contact function with existing drain contact plugs by selecting specific drain contact plugs to serve dual purposes. Instead of adding a separate well-pickup contact plug between drain contacts, the invention designates certain drain contact plugs (e.g., first and last contacts in a series) to also function as well-pickup contacts, thereby eliminating the need for additional dedicated well-pickup contacts and preventing alignment issues.
Solution Approach 2:
The patent applies multi-functionality by enabling drain contact plugs to serve multiple functions: both as drain contacts and as well-pickup contacts. This is achieved by configuring specific drain contact plugs to connect to both drain regions and well regions, allowing a single contact structure to fulfill multiple electrical connection requirements without requiring separate specialized contacts.
2Reliability
If the well-pickup contact plug is enlarged in size to ensure proper coupling, then the contact reliability improves, but substrate loss and chip size increase
Solution Approach 1:
The patent eliminates the need for separate well-pickup contact plugs by merging their function into the drain contact plug structure. This integration removes the additional substrate area that would be required for enlarged well-pickup contacts, thereby maintaining contact reliability while reducing overall chip size and substrate loss.
3Reliability
If additional well-pickup contact plugs are formed between drain contact plugs, then the well-pickup function is achieved, but the fabrication process complexity and Optical Proximity Correction requirements increase
Solution Approach 1:
The patent extracts the well-pickup contact function from the conventional separate contact plug structure and integrates it into the existing drain contact plug pattern. This extraction eliminates the need for additional lithography and etching steps that would be required to form separate well-pickup contacts, thereby simplifying the fabrication process and reducing Optical Proximity Correction complexity.
Data Source
AI summary
A semiconductor device includes a semiconductor substrate configured to include a plurality of active regions that are stretched in parallel to each other, a plurality of first contact plugs and the plurality of active regions, wherein each active region is coupled with a corresponding first contact plug, and a contact pad configured to couple with a given number of first contact plugs among the plurality of first contact plugs. Misalignment occurring at the ends of a series of drain contacts may be prevented, and the size of well-pickup contacts may be decreased by forming contact plugs that are coupled with drain regions with the same distance to a well-pickup contact region without additionally forming well-pickup contact plugs and using the contact plugs as well-pickup contact plugs. Therefore, loss of a substrate may be minimized, and burden of Optical Proximity Correction (OPC) is relieved, reducing Turn-Around Time (TAT).