Schottky Diode Diffused Design for Leakage Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing epitaxial process for manufacturing high voltage (300-600V) and high current (10-100 A) Schottky diodes is costly and prone to defects, limiting its effectiveness for high current chip technology.
Innovation Solution
A diffused design production process for Schottky diodes involving phosphorus deposition, N+ phosphorus diffusion, chemical mechanical polishing, classification based on resistivity and thickness, primary and secondary lithography, ion implantation, metal sputtering, and metal evaporation, replacing the conventional epitaxial process to form the N+ layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If epitaxial process is used to manufacture high voltage Schottky diodes, then manufacturing capability is achieved, but production cost increases and defect rate increases
Solution Approach 1:
The patent changes the fundamental manufacturing parameter from epitaxial growth to diffusion process. Specifically, it uses phosphorus diffusion to create the N+ layer instead of epitaxial growth, and uses aluminum ion implantation instead of conventional p-type diffusion. This parameter change in the manufacturing process achieves lower defect rates and reduced costs while maintaining the required electrical characteristics for high voltage Schottky diodes
Solution Approach 2:
The patent replaces the mechanical/chemical epitaxial growth process with a diffusion-based process. The diffusion process uses thermal energy to drive phosphorus atoms into the silicon substrate, creating the desired doping profile without the complexity and high cost of epitaxial equipment and processes
2Ease of manufacture
If epitaxial process is used to manufacture high voltage Schottky diodes, then manufacturing capability is achieved, but production cost increases
Solution Approach 1:
The patent changes the fundamental manufacturing parameter from epitaxial growth to diffusion process. Specifically, it uses phosphorus diffusion to create the N+ layer instead of epitaxial growth, and uses aluminum ion implantation instead of conventional p-type diffusion. This parameter change in the manufacturing process achieves lower defect rates and reduced costs while maintaining the required electrical characteristics for high voltage Schottky diodes
3Productivity
If diffusion process is used instead of epitaxial process, then production cost decreases and defect rate decreases, but manufacturing precision requirements increase
Solution Approach 1:
The patent replaces the mechanical/chemical epitaxial growth process with a diffusion-based process. The diffusion process uses thermal energy to drive phosphorus atoms into the silicon substrate, creating the desired doping profile without the complexity and high cost of epitaxial equipment and processes
Solution Approach 2:
The patent employs precise control of diffusion parameters including temperature (1275±50°C), time (175±5 hours), and phosphorus source concentration to achieve the required doping profile. The use of aluminum ion implantation with specific doses (4-5×10^19 atoms/cm²) further ensures precise control of the p-type layer characteristics
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 diffused design process significantly reduces current leakage by 30% and lowers defect rates, while lowering production costs by one third, facilitating mass production of high voltage and high current Schottky diodes.
Implementation Method 1
processing high-concentration N+ phosphorus diffusion
Implementation Method 2
processing ion implantation to form p+ layer (4 ̃5×1019 mM)
Implementation Method 3
processing metal spluttering
Implementation Method 4
processing metal evaporation for front contact side
Data Source
AI summary
A process of manufacture of high voltage (300-600V) and high current (10-100 A) Schottky diode, which includes the following steps in sequence: provide a N-type silicon wafer; process phosphor deposition and high-concentration N+ phosphorus diffusion; cutting and chemical mechanical polishing; classifying into different voltage groups; processing primary oxidation and lithography; processing boron diffusion, secondary lithography and wiring; process ion implantation and metal spluttering to form the Schottky barrier; process metal evaporation and lithography for front metal; and finally process etching and metal evaporation for rear metal. Instead of the conventional epitaxial process, a diffusion process is employed to form the N+ layer. The final product is equipped with the advantages of Schottky diode and is applicable for high voltage of 300-600V and high current of 10-100 A. The current leakage and defect rate are dramatically lowered while the cost is lowered, thus mass production is facilitated.