Manufacturing of electronics devices, continuously decreasing in size, commonly requires the vapor phase deposition of materials into small structures on a wafer, often at a nanometer scale. In this thesis the goal is to simulate vapor-phase deposition processes at a scale where fully atomistic simulations using Molecular Dynamics are no longer feasible. This is achieved by combing two methods, one simulating the gas flow and deposition processes and another method simulating the changing surface. A Particle Monte Carlo method, specifically designed for free molecular flow, the typical flow regime at this length scale, is used. The simulation of growing surfaces uses the Level Set Method. Combining these two methods requires some additional coupling steps presented in this work. With the coupled model, different deposition processes are simulated within trenches to observe how well these processes perform for achieving a uniform deposition, as well as evaluating different process conditions.:Table of Contents
List of Figures
List of Tables
List of Abbreviations
List of Symbols
1 Introduction
2 Basics
2.1 Surface deposition processes
2.1.1 Chemical Vapor Deposition
2.1.2 Atomic Layer Deposition
2.1.3 Physical Vapor Deposition
2.2 Simulation approaches for surface depositions
2.2.1 Modeling chemical reactions on a surface
2.2.2 Interaction tables for PVD
2.3 Flow regimes
2.4 Molecular Dynamics
2.5 Particle Monte Carlo
2.6 Marker Particle Method
2.7 Level Set Method
2.7.1 Re-initialization of the signed distance function
2.7.2 Extension Velocities
2.7.3 Fast Marching Method
2.7.4 Upwind scheme
2.7.5 Curvature
2.8 Marching-Squares/Cubes Algorithm
3 Methods and Implementation
3.1 Software
3.1.1 External libraries
3.1.2 Geosect
3.2 Initialization of the signed distance field
3.3 Coupling between particle simulations and Level Set
3.3.1 The simulation cycle
3.3.2 Conversion from a grid to a discrete mesh
3.3.3 Extension of growth rates from a mesh to a grid
3.4 Integrating the Level Set Equation
3.4.1 Splitting the number of particles between different steps
3.4.2 Re-initializing the signed distance function
3.4.3 Handling surface coverage
3.4.4 The full update of the surface
3.5 Curvature dependent reflow
3.6 Level Set for radial symmetry
4 Verification
4.1 Testing different integration schemes
4.1.1 Growth of a circle in a linear velocity field
4.1.2 PVD in trenches
4.2 Mass preservation during curvature dependent reflow
4.3 Comparisons between 2D, radial 2D and 3D
4.3.1 Comparing 2D and 3D
4.3.2 Comparing radial 2D and 3D
5 Process Simulations
5.1 Resputter process using a PVD
5.1.1 Simulations and their parameters
5.1.2 Surfaces after the deposition step
5.1.3 Surface growth in the resputter step
5.1.4 Conditions for improved layer thickness
5.2 CVD with an effective sticking coefficient
5.3 Incomplete ALD cycles
5.4 Deposition onto a complex 3D shape
6 Conclusion
Bibliography
Acknowledgment
Statement of authorship
| Identifer | oai:union.ndltd.org:DRESDEN/oai:qucosa:de:qucosa:78643 |
| Date | 01 April 2022 |
| Creators | Gehre, Joshua |
| Contributors | Lorenz, Erik E., Weigel, Martin, Schuster, Jörg, Technische Universität Chemnitz |
| Source Sets | Hochschulschriftenserver (HSSS) der SLUB Dresden |
| Language | English |
| Detected Language | English |
| Type | info:eu-repo/semantics/acceptedVersion, doc-type:masterThesis, info:eu-repo/semantics/masterThesis, doc-type:Text |
| Rights | info:eu-repo/semantics/openAccess |
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