Semiconductor Superjunction Trench Alignment via Self-Aligned Masks
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Solution Overview
Problem
In semiconductor devices with field effect transistors, improving area-specific on resistance (Ron×A) often requires compromising on other device properties, such as voltage blocking capability, which is not optimally addressed by existing methods.
Innovation Solution
A method involving a semiconductor body with first and second dopants of different conductivity types, forming trenches and filling them with semiconductor material, and creating a superjunction structure through self-aligned masks to optimize dopant distribution and conductivity types within the device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If self-aligned masks are used to form trenches, then manufacturing precision improves, but device complexity increases
Solution Approach 1:
The first mask is formed preliminarily to define the first trenches, and this mask structure is then used as a template for forming the second mask in a self-aligned manner. This preliminary action ensures precise alignment between trenches of different conductivity types without requiring separate alignment operations, reducing manufacturing complexity while maintaining high precision.
Solution Approach 2:
The first mask structure serves a dual purpose: it defines the first trenches and simultaneously provides the alignment reference for forming the second mask. The mask structure is self-aligned, meaning it serves its own alignment function, eliminating the need for external alignment marks or additional alignment steps, thus improving precision without proportionally increasing complexity.
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 enhances the area-specific on resistance while maintaining or improving voltage blocking capability, achieving a more balanced set of device properties.
Implementation Method 1
forming a superjunction (SJ) structure by introducing a portion of the first dopants from a region of the semiconductor body into the semiconductor filling material
Data Source
AI summary
The disclosure relates to a method for producing a semiconductor device. The method includes providing a semiconductor body having first dopants of a first conductivity type and second dopants of a second conductivity type. The method also includes forming a first trench in the semiconductor body via a first mask, and filling the first trench with a semiconductor filling material. The method further includes forming a superjunction structure by introducing a portion of the first dopants from a region of the semiconductor body into the semiconductor filling material, forming a second trench in the semiconductor body via a second mask, which is formed in a manner self-aligned with respect to the first mask, and forming a trench structure in the second trench.