Lecture 12 - Semiconductor Device Fabrication

Lecture 12 - Semiconductor Device Fabrication - 1 Minority...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 1 Minority Carrier Diffusion Equations and Semiconductor Device Fabrication Objectives: Be able to calculate carrier concentrations and currents in semiconductor devices. Understand the fabrication technologies used to fabricate integrated circuits Questions to be Answered: EE360 Lecture 12 What is a quasi-Fermi level? How do we make an integrated circuit? Quasi-Fermi levels Recall that the Fermi level is related to the equilibrium carrier concentration. BUT, we would still like a way to describe carrier concentrations even when we are not in equilibrium. (For example, when we are in steady state). So we introduce energy levels F and F the EE360 Lecture 12 So, we introduce energy levels F N and F P , the quasi-Fermi levels for electrons and holes. 2 Calculating the quasi-Fermi levels The quasi-Fermi levels obey the same relationships as the equilibrium Fermi relationships as the equilibrium Fermi level. For a non-degenerate semiconductor: EE360 Lecture 12 Relating Current to the quasi-Fermi level Find and substitute into ( ) ( ) kT F E e n p / i P i = So, p qD p q = P p P E J P p P and , F F p = J J EE360 Lecture 12 N n N F n = J 3 Semiconductor Device Fabrication Question: How do we start with a uniform piece of silicon and produce an integrated circuit? Answer: Combine certain unit processes, and repeat them several times on each wafer. Unit Processes: Oxidation Diffusion Lithography Etching EE360 Lecture 12 Diffusion Ion Implantation Etching Thin Film Deposition Oxidation Growth of silicon dioxide (SiO...
View Full Document

Page1 / 8

Lecture 12 - Semiconductor Device Fabrication - 1 Minority...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online