Photo Diode Using Oxide Semiconductor to Simplify Doping
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Solution Overview
Problem
The manufacturing process of P-I-N structure photo diodes is complex and costly due to the need for both P+ and N+ doping, which complicates the production and increases costs.
Innovation Solution
A photo diode with an intrinsic region, a P+ doping region, and an oxide semiconductor region is developed, where the intrinsic region can be made of amorphous or polycrystalline silicon, and the oxide semiconductor region includes Hf oxide, Zn oxide, or their combinations, with the P+ doping region using Group III impurities like boron, simplifying the doping process and reducing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If P+ doping and N+ doping are used to form P-I-N structure, then photo signal conversion is achieved, but manufacturing process becomes complicated and costs increase
Solution Approach 1:
The patent extracts the N+ doping step from the conventional P-I-N structure manufacturing process. Instead of forming both P+ and N+ doped regions, the invention uses only P+ doping combined with an oxide semiconductor layer to achieve the desired photodetector functionality, thereby simplifying the manufacturing process while maintaining photo signal conversion capability
Solution Approach 2:
The patent changes the material parameter by introducing oxide semiconductor (such as IGZO - indium gallium zinc oxide) as a替代 to the conventional N+ doped silicon region. This parameter change allows the device to achieve similar electrical characteristics without requiring the complex N+ doping process, thus resolving the contradiction between manufacturing simplicity and device functionality
2Reliability
If P+ doping and N+ doping are used to form P-I-N structure, then photo signal conversion is achieved, but manufacturing costs increase
Solution Approach 1:
The patent removes the N+ doping process step from the manufacturing sequence, which directly reduces manufacturing complexity and associated costs. The oxide semiconductor layer is deposited using standard sputtering or atomic layer deposition techniques that are already prevalent in semiconductor fabrication, making the transition cost-effective
Solution Approach 2:
The oxide semiconductor layer serves as a cost-effective alternative to complex N+ doped regions. Materials like IGZO can be deposited using relatively simple and inexpensive techniques compared to the additional ion implantation and annealing steps required for N+ doping, thereby reducing overall manufacturing costs while maintaining device performance
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 configuration simplifies the manufacturing process, reduces costs, and maintains appropriate resistance and current flow characteristics, enabling efficient photo signal conversion while minimizing recombination and excessive current increase.
Implementation Method 1
A photo diode having a P-I-N structure may be a semiconductor device that converts a photo signal into an electrical signal. Electrons and holes may be generated in an intrinsic region due to, e.g., photo energy
Implementation Method 2
forming a P+ doping region by doping an impurity ion on a portion of the intrinsic region. The forming of the P+ doping region may include forming a mask covering a portion of the intrinsic region that is not the portion on which the impurity ion is to be doped, implanting a Group III impurity ion into an un-masked portion of the intrinsic region
Data Source
AI summary
A photo diode includes an intrinsic region on a substrate, a P+ doping region in a first portion of the intrinsic region, and an oxide semiconductor region. The oxide semiconductor region is spaced apart from the P+ doping region on a second portion of the intrinsic region and the second portion of the intrinsic region is different from the first portion of the intrinsic region.