Semiconductor Layer Structure for Low-Resistance Zener Diodes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The simultaneous formation of a transistor with a low impurity concentration region and a diode results in increased operating resistance and leakage current due to point defects and shifted depletion layers.
Innovation Solution
A semiconductor device structure is designed with additional semiconductor layers having higher impurity concentrations, specifically a p type semiconductor layer formed simultaneously with the ZD anode layer, and optimized ion implantation parameters to position point defects outside the depletion layer, reducing operating resistance and leakage current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a transistor with a low impurity concentration region (LDD region) and a diode are simultaneously formed, then the manufacturing process efficiency is improved, but the operating resistance of the diode increases
Solution Approach 1:
The patent divides the diode structure into multiple semiconductor layers with different impurity concentrations. Specifically, it forms a first semiconductor layer with a first conductivity type and a second semiconductor layer with a second conductivity type, where the second layer has a higher impurity concentration than the first. This segmentation allows the diode to maintain low operating resistance while being formed simultaneously with the transistor's LDD region.
Solution Approach 2:
The patent applies local quality by creating regions with different impurity concentrations within the diode structure. The first semiconductor layer has a lower impurity concentration while the second semiconductor layer has a higher impurity concentration, optimizing the electrical characteristics locally to reduce operating resistance without affecting the transistor's LDD region formation.
2Device complexity
If a transistor with a low impurity concentration region and a diode are simultaneously formed, then the manufacturing process is simplified, but leakage current increases due to point defects and shifted depletion layers
Solution Approach 1:
The patent changes the impurity concentration parameter by forming a second semiconductor layer with a higher impurity concentration than the first semiconductor layer. This parameter change optimizes the depletion layer positioning and reduces point defects, thereby minimizing leakage current while maintaining the simplified simultaneous formation process.
Solution Approach 2:
The patent performs preliminary action by pre-forming the semiconductor layers with optimized impurity concentrations before final device operation. The first and second semiconductor layers are formed with specific impurity concentrations to prevent point defects and control depletion layer positioning in advance, preventing leakage current issues before they occur.
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 effectively reduces the operating resistance of the Zener diode by approximately 24% and minimizes leakage current, improving the semiconductor device's electrical characteristics and yield.
Implementation Method 1
optimized ion implantation parameters to position point defects outside the depletion layer
Data Source
AI summary
A semiconductor device has: a first semiconductor layer of a first conductivity type; a second semiconductor layer of a second conductivity type differing from the first conductivity type in the first semiconductor layer; a third semiconductor layer of the second conductivity type in the second semiconductor layer and having a higher impurity concentration than the second semiconductor layer; a fourth semiconductor layer of the first conductivity type on the third semiconductor layer; a fifth semiconductor layer of the first conductivity type on the fourth semiconductor layer and having a higher impurity concentration than the fourth semiconductor layer; a sixth semiconductor layer of the second conductivity type in the second semiconductor layer and having a higher impurity concentration than the third semiconductor layer; and a seventh semiconductor layer of the second conductivity type having the same impurity concentration distribution as the third semiconductor layer in a depth direction.