What This Document Is
This document represents a lecture reference from ELENG 143: Microfabrication Technology at UC Berkeley, specifically focusing on the critical process of dopant diffusion. It’s designed to accompany lectures and provide a detailed foundation for understanding how impurities are introduced into semiconductor materials to modify their electrical properties. This reference material delves into the theoretical underpinnings and practical considerations of diffusion techniques used in microfabrication.
Why This Document Matters
This resource is invaluable for students enrolled in microfabrication courses, semiconductor physics, or related engineering disciplines. It’s particularly helpful when studying the creation of p-n junctions, transistors, and other essential semiconductor devices. Professionals working in the semiconductor industry will also find it a useful refresher on fundamental diffusion principles. Use this reference to solidify your understanding of the concepts presented in lectures and to prepare for more advanced topics in device fabrication.
Topics Covered
* Dopant sources and their characteristics (gas, solid, liquid, and spin-on glass)
* Solid solubility of impurities in silicon at varying temperatures
* Diffusion coefficients of common impurities and their temperature dependence
* Mathematical models governing diffusion processes, including Fick’s Laws
* Predeposition and drive-in diffusion techniques
* The influence of boundary conditions on diffusion profiles
* Approximations and practical considerations for solving diffusion equations
* Calculating dopant dose and concentration gradients
What This Document Provides
* Detailed explanations of the Arrhenius relationship as it applies to diffusion.
* Illustrative representations of dopant diffusion processes.
* Mathematical formulations for analyzing diffusion behavior.
* Discussions on the concentration independence of diffusion.
* Properties of the error function and complementary error function used in diffusion modeling.
* Practical approximations for calculating error functions.
* Formulas for calculating predeposition dose and concentration gradients.
