Plasma-Activated Conformal Film Deposition on Substrates
Solution Overview
Problem
Atomic layer deposition (ALD) processes for semiconductor devices often result in incomplete film deposition, film islanding, and thickness variations due to unsaturated wafer conditions, leading to inadequate device performance and reduced throughput.
Innovation Solution
A method involving the use of plasma-activated conformal film deposition (CFD) using silicon-containing reactants like di-tert-butyl diazidosilane and tris(dimethylamido)silylazide, where reactants are introduced in vapor phase and exposed to plasma, allowing for continuous flow and reduced sweep times, enabling conformal film formation on non-planar substrates with improved step coverage and reduced processing time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If longer dosing times are used to saturate the wafer surface with film precursor, then complete film deposition is achieved, but process tool throughput decreases and valuable precursor is wasted during film nucleation phases
Solution Approach 1:
The patent changes the chemical parameters by selecting specific silicon-containing reactants from a precursor group (di-tert-butyl diazidosilane, tris(dimethylamido)silylazide, or bis(tert-butylhydrazido)diethylsilane) that enable complete film deposition under optimized conditions, achieving saturation without extended dosing times
Solution Approach 2:
The patent introduces the silicon-containing reactant in vapor phase under conditions that allow it to adsorb onto the substrate surface before plasma introduction, preparing the surface in advance for immediate reaction when plasma is introduced, eliminating the need for extended dosing times
2Manufacturing precision
If longer dosing times are used to saturate the wafer surface, then complete film deposition is achieved, but extended processing time requires installation and maintenance of additional process tools
Solution Approach 1:
The patent optimizes process parameters including temperature (less than or equal to 400°C) and reactant selection to achieve complete film deposition within a single process tool's capabilities, eliminating the need for additional tools
Solution Approach 2:
The reactant is introduced and allowed to adsorb onto the substrate surface in advance, preparing the surface for immediate reaction when plasma is introduced, enabling complete deposition in a single tool without requiring multiple sequential tools
3Quantity of substance
If conventional ALD processes are used, then film deposition occurs, but incomplete film deposition, film islanding, and film thickness variation result
Solution Approach 1:
The patent changes key process parameters including introducing plasma activation and selecting specific silicon-containing reactants from a precursor group, which enables complete and uniform film deposition without the islanding and thickness variation problems of conventional ALD
Solution Approach 2:
The patent replaces the purely thermal reaction mechanism of conventional ALD with a plasma-activated reaction mechanism, where plasma provides the activation energy for complete surface coverage and uniform film formation, eliminating the need for extended dosing times and preventing film islanding
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 ensures complete and conformal film deposition on non-planar substrates, enhancing device performance by reducing thickness variations and increasing production throughput while maintaining physical and electrical characteristics.
Implementation Method 1
introducing the silicon-containing reactant in vapor phase into the reaction chamber under conditions allowing the silicon-containing reactant to adsorb onto the substrate surface
Implementation Method 2
exposing the substrate surface to plasma to drive a reaction between the silicon-containing reactant and the second reactant on the substrate surface to form the film
Implementation Method 3
drive a reaction between the silicon-containing reactant and the second reactant on the substrate surface to form the film
Data Source
AI summary
A method of depositing a film on a substrate surface includes providing a substrate in a reaction chamber; selecting a silicon-containing reactant from a precursor group consisting of di-tert-butyl diazidosilane, bis(ethylmethylamido)silane, bis(diisopropylamino)silane, bis(tert-butylhydrazido)diethylsilane, tris(dimethylamido)silylazide, tris(dimethylamido)silylamide, ethylsilicon triazide, diisopropylaminosilane, and hexakis(dimethylamido)disilazane; introducing the silicon-containing reactant in vapor phase into the reaction chamber under conditions allowing the silicon-containing reactant to adsorb onto the substrate surface; introducing a second reactant in vapor phase into the reaction chamber while the silicon-containing reactant is adsorbed on the substrate surface, and wherein the second reactant is introduced without first sweeping the silicon-containing reactant out of the reaction chamber; and exposing the substrate surface to plasma to drive a reaction between the silicon-containing reactant and the second reactant on the substrate surface to form the film.