Semiconductor Inspection Patterns for Process Center Monitoring
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Solution Overview
Problem
As semiconductor devices become smaller, the rate of random defects increases, making it challenging to detect changes in the process center before yield reduction occurs, leading to time and resource losses.
Innovation Solution
A semiconductor device with a substrate inspection pattern that includes normal and defective patterns in a dummy area, allowing for early detection of process center changes by intentionally forming defects to reduce the process window and monitor deviations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the process center is monitored after yield reduction occurs, then defects can be detected, but time and physical resources are lost
Solution Approach 1:
The patent applies preliminary action by placing inspection patterns with intentional defects in advance on the semiconductor substrate before actual production. These pre-positioned patterns allow the system to detect process center deviations before they affect yield, enabling proactive process correction rather than reactive detection after damage occurs.
Solution Approach 2:
The inspection patterns serve as an intermediary element between the process center and the actual product. By monitoring these intermediate patterns that contain known defects, the system can infer process center status without directly testing production units, thus detecting issues before they propagate to yield-critical areas.
2Length of moving object
If fine patterns are realized to make semiconductor devices smaller, then device miniaturization is achieved, but the rate of random defects increases
Solution Approach 1:
The patent extracts the inspection function from the active production area and places it in a dummy area of the substrate. By separating inspection patterns from circuitry patterns, the system can monitor process quality without interfering with miniaturized device fabrication, allowing fine pattern realization while maintaining defect monitoring capability.
Solution Approach 2:
The inspection patterns are copies of actual circuit patterns but placed in non-functional dummy areas. These copied patterns replicate the geometric features and process sensitivity of real devices, allowing defect rate monitoring for miniaturized structures without consuming active device area, thus supporting continued device scaling.
3Measurement precision
If inspection patterns are placed in the active area, then process monitoring is achieved, but the area available for circuitry is reduced
Solution Approach 1:
The patent segments the substrate into distinct functional zones: active areas for circuitry and dummy areas for inspection patterns. This spatial segmentation allows simultaneous optimization of both production area and monitoring capability, with inspection functions isolated to non-functional regions that would otherwise be waste space.
Solution Approach 2:
The patent recovers unused dummy areas of the substrate by placing inspection patterns there. These areas would normally be discarded as non-functional space, but by utilizing them for process monitoring, the system transforms waste area into valuable quality control resources without encroaching on active circuitry regions.
Data Source
AI summary
A semiconductor device includes a first normal pattern which is disposed in an active area of a semiconductor chip, wherein the first normal pattern has a particular shape and the active area includes circuitry for operating the semiconductor chip, and includes a first defective pattern and a second normal pattern which are disposed in a dummy area of the semiconductor chip, wherein the dummy area of the semiconductor chip is an area that does not perform functions for operating the semiconductor chip. The second normal pattern has the same shape as the first normal pattern and the first defective pattern has the same shape as the first normal pattern except for a first defect. The first normal pattern is disposed at a first level layer of the semiconductor chip. The first defective pattern comprises a first part and a second part, and the second normal pattern comprises a third part corresponding to the first part and that matches the first part in shape and size and a fourth part corresponding to the second part, wherein the second part includes the first defect and matches the fourth part in shape and size except for the first defect. If the second part and fourth part were to be superimposed over each other, the second part would include a piece of material that is absent from the fourth part and that comprises the first defect.