Back Side Drawn Electrode Alignment Mark Integration
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Solution Overview
Problem
The existing back side illumination CMOS image sensor manufacturing process is inefficient due to the separate steps required for forming electrodes and alignment marks, leading to increased complexity and limitations in miniaturization, as the alignment mark needs to be remodeled into a back side drawn electrode, which complicates the process and hinders size reduction.
Innovation Solution
A semiconductor device and method where a back side drawn electrode is formed by embedding a conductive material in a contact hole through an insulating film with a uniform thickness, serving both as an electrode and alignment mark, thereby simplifying the process and enabling miniaturization by integrating the formation of the alignment mark and back side drawn electrode into a single step.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If separate steps are used for forming electrodes and alignment marks, then the manufacturing process can be completed, but the process complexity increases and miniaturization is limited
Solution Approach 1:
The patent merges the formation of the alignment mark and the back side drawn electrode into a single integrated structure. The alignment mark is formed with a conductive layer that simultaneously serves as the electrode, eliminating the need for separate formation steps and reducing process complexity while maintaining alignment accuracy.
Solution Approach 2:
The alignment mark structure is designed to perform multiple functions: it serves as both an alignment reference for lithography and as a functional electrode for electrical connection. This multi-functionality reduces the number of separate components and manufacturing steps required.
2Ease of manufacture
If the alignment mark is remodeled into a back side drawn electrode, then the electrode function is achieved, but the manufacturing steps increase
Solution Approach 1:
The conductive layer is formed as part of the alignment mark structure during the alignment mark formation process itself, before the electrode formation steps. This preliminary action eliminates the need for separate electrode formation steps and accelerates manufacturing.
3Ease of manufacture
If traditional separate formation methods are used, then manufacturing is straightforward, but the device size cannot be reduced
Solution Approach 1:
By combining the alignment mark and electrode into a single integrated structure, the patent reduces the overall device footprint. The merged structure eliminates the need for separate alignment mark and electrode components, enabling miniaturization while maintaining ease of manufacturing through standard fabrication processes.
Data Source
AI summary
A semiconductor device includes a semiconductor substrate, a back side drawn electrode formed by embedding a first conductive material in a contact hole penetrating the semiconductor substrate through an insulating film formed to include a uniform thickness, used also as an alignment mark, and configured to draw out an electrode to the back side of the semiconductor substrate. The device further includes a pad provided on the back side of the semiconductor substrate, and connected to the back side drawn electrode.