Selective Etching of Sn-Containing Group IV Materials
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current selective etching processes in semiconductor manufacturing, particularly for gate-all-around field effect transistors, face challenges in achieving adequate selectivity between Sn-containing Group IV materials and other Group IV materials, leading to geometry loss and performance issues due to limited etch selectivity.
Innovation Solution
A method involving the use of chlorine-based or bromine-based etching gases in a process chamber to selectively etch a Sn-containing Group IV material with respect to a second Group IV material, where the Sn-containing material includes a dopant element, allowing for improved etch selectivity and controlled, uniform etching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional selective etching processes are used to remove sacrificial layers, then the etching process can proceed, but etch selectivity between Sn-containing Group IV materials and other Group IV materials is insufficient, leading to geometry loss of channel layers
Solution Approach 1:
The patent changes the chemical composition parameters of the etching gas by introducing fluorine-containing gases (CF4, SF6, C4F8) combined with chlorine-based or bromine-based gases. This parameter change creates a highly selective etching chemistry that selectively removes Sn-containing Group IV materials while preserving other Group IV materials, achieving the required etch selectivity without geometry loss
Solution Approach 2:
The patent uses composite etching gas formulations combining fluorine-containing gases with chlorine-based or bromine-based gases. This composite approach creates synergistic effects where the fluorine component provides selective bonding to Sn-containing materials while the chlorine/bromine component enhances the etching rate and selectivity, solving the contradiction between maintaining precision and enabling effective etching
2Manufacturing precision
If etch selectivity is improved to preserve channel layers, then geometry loss is reduced, but the etching process complexity increases due to specific gas composition requirements
Solution Approach 1:
The patent establishes specific parameter ranges for the etching gas composition (fluorine-containing gas at 1-50 sccm, chlorine-based gas at 1-20 sccm, pressure at 10-100 mTorr, power at 50-200 W). These defined parameters create a standardized process that, while specific, provides reproducible results and reduces operational complexity through clear process windows
Solution Approach 2:
The patent replaces conventional physical or simple chemical etching mechanisms with a plasma-based etching system using specifically formulated gas mixtures. This substitution provides more precise control over the etching process through plasma parameters (power, pressure, gas flow), enabling high selectivity while maintaining processability through well-established plasma etching equipment
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 etch selectivity, preserving the dimensions of the second feature and improving the manufacturing process by ensuring precise geometry retention during the etching of horizontal gate-all-around field effect transistors, thereby reducing manufacturing costs and improving device performance.
Implementation Method 1
The substrate is heated in the process chamber
Implementation Method 2
An etch process is performed comprising introducing, into the process chamber, an etching gas and subjecting the substrate to the etching gas, wherein the etching gas is a chlorine-based or a bromine-based gas
Data Source
Figure 1~2b
Figure 3a~4
AI summary
Method for removing a first feature comprising a Sn-containing first Group IV material selective to a second feature comprising a second Group IV material, the method comprising: - providing, in a process chamber, a substrate having an upper surface, wherein the first feature and the second feature are arranged on the upper surface, wherein the Sn-containing first Group IV material comprises a dopant element, - heating, in the process chamber, the substrate, and thereafter; - performing an etch process comprising: ∘ introducing, into the process chamber, an etching gas, ∘ subjecting the substrate to the etching gas, wherein the etching gas is a chlorine-based or a bromine-based gas.