FinFET Recessed Stress Layer for Mobility Without Fin Bending
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In the semiconductor industry, particularly with FinFET technology, there is a challenge in applying stress to the channel region of transistors to enhance mobility without causing manufacturing issues such as fin bending or insufficient stress induction, which affects device performance.
Innovation Solution
A stress-inducing material is formed in a recess extending into the semiconductor layer below the fin, using a dielectric material or silicon alloy, which applies stress to the channel region through a combination of deposition and annealing processes to achieve optimal tensile or compressive stress, thereby enhancing mobility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If stress-inducing material is applied to the channel region to enhance mobility, then carrier mobility is improved, but fin bending or warping occurs causing manufacturing defects
Solution Approach 1:
The stress-inducing material is segmented into two distinct regions: a first stress-inducing material in the source region and a second stress-inducing material in the drain region. This segmentation allows independent stress application to different parts of the channel, enhancing carrier mobility while the symmetric arrangement prevents net bending moments that would cause fin warping.
Solution Approach 2:
Different stress-inducing materials are applied locally to specific regions: the source region receives one type of stress-inducing material while the drain region receives another. This local differentiation optimizes stress distribution to improve carrier mobility in the channel while preventing uniform stress that would cause fin bending.
2Manufacturing precision
If stress-inducing material is formed deep in the recess to avoid fin bending, then manufacturing precision is improved, but stress induction becomes insufficient affecting device performance
Solution Approach 1:
The stress-inducing materials are formed with different depths in the recess: the first stress-inducing material extends to a first depth while the second stress-inducing material extends to a second depth. This dynamic depth variation allows stress to be applied at optimal locations in the channel region, ensuring sufficient stress induction for carrier mobility enhancement while maintaining fin structural integrity.
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 increases hole mobility for P-type transistors and carrier mobility for N-type transistors, improving device performance by minimizing resistance and avoiding manufacturing defects like fin warping.
Implementation Method 1
using a dielectric material or silicon alloy, which applies stress to the channel region through a combination of deposition and annealing processes to achieve optimal tensile or compressive stress
Data Source
AI summary
A method for forming a semiconductor arrangement comprises forming a fin over a semiconductor layer. A gate structure is formed over a first portion of the fin. A second portion of the fin adjacent to the first portion of the fin and a portion of the semiconductor layer below the second portion of the fin are removed to define a recess. A stress-inducing material is formed in the recess. A first semiconductor material is formed in the recess over the stress-inducing material. The first semiconductor material is different than the stress-inducing material.