Transistor Source/Drain Interface Layer for Dopant Control
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Solution Overview
Problem
In modern integrated circuits, the reduction in transistor size to improve performance and packing density has led to challenges in managing dopant materials in the channel region, affecting electrical performance characteristics.
Innovation Solution
The introduction of an interface layer comprising a non-semiconductor material in the source/drain regions of transistor devices, which limits dopant diffusion and imparts desired stress profiles, is used in conjunction with epitaxial semiconductor material growth to enhance transistor performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the physical size of transistors is reduced to improve performance and packing density, then switching speed improves and packing density increases, but control over dopant materials in the channel region becomes difficult, affecting electrical performance characteristics
Solution Approach 1:
The source/drain region is segmented into multiple functional layers: a non-semiconductor interface layer at the bottom, an epi semiconductor layer in the middle, and a doped semiconductor layer on top. This segmentation allows the dopant distribution to be controlled by limiting dopant diffusion into the channel region through the interface layer, while still achieving high packing density and switching speed through the overall miniaturized structure.
Solution Approach 2:
A non-semiconductor interface layer is introduced as an intermediary between the substrate and the semiconductor material in the source/drain region. This interface layer acts as a barrier that limits dopant diffusion into the channel region, thereby improving control over dopant distribution while maintaining the benefits of reduced transistor size.
2Reliability
If dopant materials are limited in the channel region to improve electrical performance characteristics, then electrical performance improves, but traditional source/drain region formation becomes insufficient
Solution Approach 1:
The source/drain region is divided into distinct layers with different functions: the interface layer prevents unwanted dopant diffusion, the epi layer provides a controlled growth medium, and the doped layer supplies necessary dopants. This segmentation enables improved electrical performance by limiting dopant in the channel while simplifying manufacturing through controlled epitaxial growth and doping processes.
Solution Approach 2:
The invention changes the material parameters of the source/drain region by introducing a non-semiconductor interface layer with specific properties that limit dopant diffusion. This parameter change allows for improved electrical performance characteristics while maintaining ease of manufacture through standard epitaxial growth and doping techniques adapted to the new layered structure.
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 improves electrical performance by controlling dopant distribution and stress profiles within the channel region, leading to enhanced switching speed and increased packing density in integrated circuits.
Implementation Method 1
the interface layer comprises a non-semiconductor material and an epi semiconductor material positioned on at least an upper surface of the interface layer in the epi cavity in each of the source region and the drain region
Implementation Method 2
an epi semiconductor material positioned on at least an upper surface of the interface layer in the epi cavity in each of the source region and the drain region
Data Source
AI summary
One illustrative transistor device disclosed herein includes a gate structure positioned above a semiconductor substrate and a source region and a drain region, each of which comprise an epi cavity with a bottom surface and a side surface. The transistor further includes an interface layer positioned on at least one of the side surface and the bottom surface of the epi cavity in each of the source/drain regions, wherein the interface layer comprises a non-semiconductor material and an epi semiconductor material positioned on at least an upper surface of the interface layer in the epi cavity in each of the source region and the drain region.