Light Detection Device Indium Diffusion Barrier
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional light detection devices for near-infrared light using indium bumps experience connection failures due to indium diffusion at high temperatures, making them unreliable for use in high-temperature environments such as vehicles or satellites.
Innovation Solution
The light detection device employs conductive connection parts with a Ti layer and a Pt layer stacked on the semiconductor layer, and an indium layer covering the connection core layer, which suppresses indium diffusion and enhances adhesion, ensuring reliable connections between the photo detector and the circuit board even at high temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If indium bumps are used to connect the photo detector and circuit board, then electrical connection is achieved, but connection failure occurs at high temperatures due to indium diffusion
Solution Approach 1:
A Ti layer and Pt layer are introduced as intermediary layers between the indium bump and the semiconductor layer. These intermediary layers act as diffusion barriers that prevent indium atoms from migrating into the semiconductor, while still allowing electrical conduction. The Ti layer provides adhesion to the semiconductor surface, and the Pt layer provides a diffusion barrier against indium, creating a protective interface structure.
Solution Approach 2:
The electrode structure is designed as a composite of multiple materials (Ti layer, Pt layer, and indium bump) with complementary properties. The Ti layer offers good adhesion and electrical conductivity, the Pt layer provides excellent diffusion barrier properties and conductivity, and the indium bump provides low-resistance electrical connection. This composite structure combines the advantages of each material to achieve both electrical connectivity and diffusion prevention.
2Reliability
If a diffusion barrier layer is added to prevent indium diffusion, then connection reliability improves, but device structure becomes more complex
Solution Approach 1:
The thickness parameters of the Ti and Pt layers are optimized to achieve the desired balance between diffusion prevention and electrical conductivity. By carefully controlling the layer thicknesses (typically tens to hundreds of nanometers), the structure provides effective diffusion barriers while maintaining low electrical resistance. This parameter optimization allows the use of standard thin-film deposition techniques without requiring complex thick barrier structures.
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
The solution significantly improves the reliability of the light detection device by preventing indium diffusion and maintaining electrical connections under high-temperature conditions, thus ensuring the device's functionality is maintained over extended periods.
Implementation Method 1
Each of the first electrodes includes a Ti layer and a Pt layer stacked in this order on the semiconductor layer, and the conductive connection parts are provided on the Pt layers of the first electrodes
Implementation Method 2
Each of the first electrodes includes a Ti layer and a Pt layer stacked in this order on the semiconductor layer, and the conductive connection parts are provided on the Pt layers of the first electrodes
Data Source
AI summary
A light detection device includes a photo detector and a circuit board connected to the photo detector by conductive connection parts. In this light detection device, the photo detector includes a substrate, a semiconductor layer provided on one surface of the substrate, a first groove dividing the semiconductor layer into sections for respective pixels, and first electrodes provided on the semiconductor layer and serving as the pixels. Each of the conductive connection part contains indium. Each of the first electrode includes a Ti layer and a Pt layer stacked in this order on the semiconductor layer, and the conductive connection parts are provided on the Pt layers of the first electrodes.