Optical Receiver UV Sensitivity Noise Reduction
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Solution Overview
Problem
Existing optical receivers suffer from high noise levels in the visible light and infrared regions due to differences in reflection and transmission characteristics between light-receiving devices with and without UV cut filters, which interfere with precise ultraviolet light detection.
Innovation Solution
The optical receiver design includes a first and second light-receiving device with the same structure, where the first device is equipped with a UV cut filter, and both devices are electrically short-circuited, with insulating films of different materials laminated between them to minimize noise and enhance sensitivity in the ultraviolet region.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a UV cut filter is formed on the first light-receiving device, then ultraviolet light detection sensitivity is improved, but noise in the visible light region and infrared light region increases
Solution Approach 1:
The light-receiving devices are segmented into three distinct diffusion layers (first, second, and third diffusion layers) with different junction depths. This segmentation allows each layer to respond differently to various wavelength regions, enabling the system to distinguish between ultraviolet light signals and visible/infrared noise through differential measurement.
Solution Approach 2:
The invention changes the structural parameters of the light-receiving devices by forming multiple diffusion layers with different junction depths. This parameter change creates devices with differentiated spectral responses, allowing the system to maintain high ultraviolet sensitivity while suppressing visible and infrared noise through mathematical processing of the differential signals.
2Measurement precision
If the semiconductor substrate, first diffusion layer, and second diffusion layer are electrically at the same potential or short-circuited, then sensitivity variations in the ultraviolet region are reduced, but device structure complexity increases
Solution Approach 1:
The semiconductor substrate, first diffusion layer, and second diffusion layer are electrically connected to maintain the same potential or short-circuit condition. This equipotential configuration ensures that all three diffusion layers respond uniformly to ultraviolet light, reducing sensitivity variations and improving measurement consistency.
Solution Approach 2:
The invention merges the electrical potentials of the semiconductor substrate, first diffusion layer, and second diffusion layer by establishing electrical connections between them. This merging creates a unified electrical system that responds consistently to ultraviolet light while maintaining the structural complexity required for noise suppression.
3Object-generated harmful factors
If insulating films of different materials are laminated between light-receiving devices, then noise minimization is improved, but manufacturing process complexity increases
Solution Approach 1:
The invention uses insulating films made of different materials laminated between the light-receiving devices. This composite material approach provides superior noise isolation compared to single-material films, as the different materials work together to block various types of electrical interference and crosstalk between adjacent devices.
Solution Approach 2:
The laminated insulating films serve as intermediary layers between the light-receiving devices, providing electrical isolation and noise suppression. These intermediary films prevent direct electrical coupling between adjacent devices, thereby minimizing noise while requiring additional manufacturing steps for lamination.
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 reduces sensitivity variations in the ultraviolet region and minimizes noise in the visible and infrared regions, enabling precise ultraviolet light detection with improved accuracy.
Implementation Method 1
a filter cutting a wavelength in an ultraviolet region
Implementation Method 2
a photoelectric conversion element having a high sensitivity to ultraviolet light is necessary
Data Source
AI summary
Provided are an optical receiver that can realize a reduction in the variation of sensitivity in the ultraviolet light region and a reduction in noise in the visible light region and the infrared light region, a portable electronic device, and a method of producing an optical receiver. The first light-receiving device (PD1) and the second light-receiving device (PD2) of the optical receiver (1) are each constituted by forming a second conductivity-type N-type well layer (N_well) on a first conductivity-type P-type substrate (P_sub), forming a first conductivity-type P-type well layer (P_well) in the N-type well layer (N_well), and forming a second conductivity-type N-type diffusion layer (N) in the P-type well layer (P_well). The P-type substrate P_sub, the N-type well layer (N_well), and the P-type well layer (P_well) are electrically at the same potential or are short-circuited.