Inline Sensor Array Defect Repair via Dual Lithographic Masking
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Solution Overview
Problem
Defects in imaging sensor arrays caused by particles and flakes during manufacturing lead to device failure and low yield, as they obstruct etching processes and result in short circuits between pixels and data lines, necessitating effective inline repair methods that do not cause further damage.
Innovation Solution
The method involves a cleaning step to remove particles, using a second lithographic mask to protect features, and a second etching step to remove obstructed material, with photoresist layers of varying sizes to ensure precise re-etching and prevent over-etching, allowing for inline repair of defects without damaging the sensor array.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If laser repair is used to repair defective sensor arrays, then some defects can be corrected, but the physical ablation process causes further damage to the sensor array structures
Solution Approach 1:
The patent applies preliminary action by performing a second lithographic masking and etching process immediately after detecting defects, before the sensor array undergoes further manufacturing steps. This inline repair approach prevents defect propagation without requiring post-manufacturing laser repair that would cause additional damage.
Solution Approach 2:
The patent extracts and removes defective material through a targeted second etching process that specifically addresses detected defects. By using a second photoresist layer with adjusted patterns, the method selectively removes only the obstructing particles and residues while preserving the surrounding functional structures.
2Reliability
If a second lithographic mask and etching process is used to repair defects, then obstructing particles and residues can be removed, but the process complexity increases
Solution Approach 1:
The patent merges the defect repair process with the existing manufacturing flow by integrating a second lithographic masking and etching step into the inline manufacturing sequence. This combination allows defect removal to be performed without requiring separate offline repair equipment or processes, thereby managing complexity within the established manufacturing framework.
3Manufacturing precision
If photoresist layers of varying sizes are used for precise re-etching, then over-etching is prevented, but the manufacturing steps increase
Solution Approach 1:
The patent applies local quality by using a second photoresist layer with spatially varying patterns where the photoresist coverage area is specifically adjusted based on local defect locations. This allows precise control of the etching process at defect sites while maintaining normal processing elsewhere, achieving high precision without uniformly increasing process steps across the entire wafer.
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
This approach effectively removes obstructing particles and residues, preventing short circuits and enhancing yield by ensuring the morphology of the sensor array corresponds to the intended design, thereby improving the manufacturing process's efficiency and product quality.
Implementation Method 1
patterning the top electrode layer, the sensor material layer, and the bottom electrode layer using a first photoresist layer to form a plurality of pixels
Data Source
AI summary
A method of manufacturing an sensor array includes providing a glass substrate; forming a bottom electrode layer over the glass substrate; forming a sensor material layer over the bottom electrode layer; forming a top electrode layer over the sensor material layer; patterning the top electrode layer, the sensor material layer, and the bottom electrode layer using a first photoresist layer to form a plurality of pixels; detecting a defect in the plurality of pixels; and patterning the plurality of pixels using a second photoresist layer. The first photoresist layer includes a plurality of first pixel patterns and the second photoresist layer comprises a plurality of second pixel patterns, and wherein at least one of the second pixel patterns has an area greater than that of a corresponding first pixel pattern.