LDMOS Fabrication via Buffer Insulation and Blocking Patterns
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High voltage semiconductor devices face challenges in controlling the doping concentration of the channel region due to the well proximity effect during ion implantation, leading to increased on-resistance and unstable operation of LDMOS transistors.
Innovation Solution
The method involves forming blocking patterns over a buffer insulation layer to prevent impurity ions from being scattered into unwanted regions during ion implantation, thereby controlling the doping concentration in the channel region by using an ion implantation mask pattern with specific openings to expose the blocking patterns and implanting impurity ions into the body region.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If ion implantation is performed to form the body region, then the doping concentration can be controlled, but the well proximity effect causes impurity ions to scatter into unwanted regions leading to increased on-resistance
Solution Approach 1:
A buffer insulation layer is introduced as an intermediary layer between the ion implantation mask pattern and the semiconductor region. This buffer layer prevents direct contact between the mask pattern and the semiconductor surface, thereby blocking the scattering of impurity ions into unwanted regions while still allowing controlled ion implantation into the body region, resolving the contradiction between doping precision and device stability
Solution Approach 2:
The semiconductor device structure is segmented by introducing the buffer insulation layer that physically separates the ion implantation process zone from the underlying semiconductor region. This segmentation allows the ion implantation to be confined to specific areas (body region) while preventing lateral scattering into adjacent regions, thus improving both doping concentration control and device reliability
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 approach effectively suppresses the well proximity effect, ensuring accurate doping concentration control and reducing on-resistance, thereby enhancing the stability and performance of high voltage semiconductor devices.
Implementation Method 1
implanting impurity ions of a first conductivity type for forming a body region of the first conductivity type into the first region using the ion implantation mask pattern
Implementation Method 2
blocking impurity ions over a buffer insulation layer disposed over a first region
Data Source
AI summary
A method includes forming a blocking pattern on a buffer insulation layer disposed over a first region in a semiconductor region of a second conductivity type, forming an ion implantation mask pattern having an opening over the buffer insulation layer to expose the blocking pattern by the opening of the ion implantation mask pattern, and implanting impurity ions of a first conductivity type for forming a body region of the first conductivity type into the first region using the ion implantation mask pattern.