Semiconductor Fin Etching With Sidewall Recess Profile Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As semiconductor devices continue to scale down in size, there is a need for improved manufacturing methods to create three-dimensional multi-gate structures like FinFETs, which require precise control over fin profiles and electrical properties.
Innovation Solution
The method involves performing multiple etching cycles with specific etching processes and polymer layer formations to create semiconductor fins with tailored profiles, including neck portions adjacent to source/drain structures, to enhance electrical control and reduce leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multiple etching cycles with polymer layer formations are performed to create fins with precise profiles, then manufacturing precision is improved, but device complexity increases
Solution Approach 1:
The etching process is divided into multiple discrete cycles, each forming a specific portion of the fin profile. Each cycle includes depositing a polymer layer and performing an etching step, allowing incremental shaping of the fin structure with precise control over each segment of the profile.
Solution Approach 2:
Polymer layers are deposited beforehand to protect specific regions during etching. The polymer layers are formed in advance of the etching steps they will protect, allowing precise control over which areas are etched and which are preserved, thereby achieving complex fin profiles through pre-planned protective actions.
2Reliability
If neck portions are formed adjacent to source/drain structures, then electrical control is improved, but manufacturing precision requirements increase
Solution Approach 1:
The fin structure is given different local properties through the formation of neck portions at specific locations adjacent to source/drain structures. These neck portions create varying widths along the fin, with narrower sections where electrical control is needed and wider sections elsewhere, allowing tailored electrical characteristics in different regions of the same 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 enables the formation of semiconductor fins with precise profiles, improving electrical control and reducing leakage, thereby enhancing the performance of FinFET devices.
Implementation Method 1
performing a first etching process on the openings; and performing a second etching process on the openings
Implementation Method 2
forming a plurality of polymer layers on surfaces of the openings
Data Source
AI summary
A method of manufacturing a semiconductor device includes at least the following steps. A protrusion is formed in a substrate by an anisotropic etch process, wherein a sidewall of the protrusion is inclined. A recess is formed on the sidewall of the protrusion by an isotropic etch process, wherein during the isotropic etch process, a by-product covers a first portion of the sidewall of the protrusion while exposing a second portion of the sidewall of the protrusion, so that the recess is formed between the first portion and the second portion of the sidewall.