SEMICONDUCTOR DEVICE FABRICATION

AN OVERVIEW

Presented to

EE 1001

11 October 2012

by

Stan Burns

sburns@d.umn.edu

MWAH 153

OUTLINE

What is a Monolithic Integrated Circuit (IC)? Dimensions State-of-the-art in size and density Materials Basic process sequence Photolithography Define some key terms Typical Device Cross-Sections Packaging Challenges and Opportunities in the Semiconductor

Industry For EE Graduates

DIMENSIONS AND UNITS 1 micrometer (1 m) = 10-6m = 10-4cm 1 Å = 10-10m = 10-8cm (Å =Angstrom) 10,000 Å = 1 m = 1000 nm 1 nanometer (1 nm) = 10-9 m = 10 Å Wavelength of visible light 0.4 m(violet) to 0.7 m(red)

{400 nm to 700 nm, 4,000 Å to 7,000 Å } 1 mil = 0.001 inch = 25.4 m Sheet of notebook paper about 4 mils 1 human hair = 75 m to 100 m = 75,000-100,000 nm Atomic spacing in a crystal ~ 3 to 5 Å Fingernail growth rate about 1-3 m/hour (Not personally verified) Aggressive production minimum feature sizes ~0.022 to 0.12 m

i.e. tens of nm Research and some prototypes< 0.022 m = < 22 nm

Integrated Circuit Overview

Stanley G. Burns

UMD-ECE

<$50

OTHER DEVICES AND TECHNOLOGIES

Thin-Film Transistors (TFT) Displays-Liquid Crystal Displays (LCD), Plasma, LED Backlit, etc. Photonic-Light Emitting Diodes (LED), Organic Light Emitting Diodes

(OLED), LASERS, Optical Chips, etc.) Photovoltaics-Conventional Crystalline and Flexible Thin-Film Devices and Systems on Flexible Substrates Micro-Electro-Mechanical Systems (MEMS) integration of mechanical

elements, sensors, actuators, and electronics on a common silicon substrate through microfabrication technology. Electronics are fabricated using integrated circuit (IC) process sequences (e.g., CMOS, Bipolar, or BICMOS processes) Micromechanical components are fabricated using compatible "micromachining"

processes that selectively etch away parts of the silicon wafer or add new structural layers to form the mechanical and electromechanical devices.

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BASIC PROCESSING STEPSDesign Then

Repeated Application Of:Oxidation

Nitridation

Photolithography

Wet Etching (Chemical)

Dry Etching (Plasma)

Diffusion

Evaporation

Sputtering

Plasma Assisted Deposition

Ion Implantation

Epitaxy

Many Processing Steps are at temperatures to 1200°C

EE Student Challenges in the Semiconductor Industry

Design devices Design circuits and systems Device modeling System design and fabrication Circuit/system simulations

Testability

Materials

How small? Nanomaterials?

How large?

Speed and performance, for analog, digital and mixed-mode applications

Increased functionality

Biological integration

Optoelectronic integration

Displays

Sensors

MEMs (Design/Application)

Non-traditional substrates

Packaging

Process development

Process Control “Tool” and plant design Cradle to grave materials handling