ENSC495/851: Introduction to Microelectronic Fabrication

SFU Eng. Science Course Outline 98-1 (Spring)

(ENSC 495, 4 credits, split as 2-0-4: ENSC 851, 3 credits, 2- 0-1)

Description

This course gives students a hands-on introduction to Integrated Circuit Fabrication. The lectures introduce the theoretical background and application of each major IC fabrication processes: eg. oxidation, doping, depositions, photolithography and etching. Process simulation tools will be used throughout the course help understand each process. In parallel the laboratory gives practical experience of each process as part of an IC the students build from the bare silicon to final working device.

Professor:

Glenn Chapman, Rm ASB 8831, Phone: 291-3814, email: glennc@cs.sfu.ca

Laboratory Engineer

Bill Woods, Rm ASB 8832

Primary text:

"Microelectronic Processing", W.S. Ruska, McGraw-Hill.

Other references:

"The Science and Engineering of Microelectronic Fabrication", Stephen Campbell, Oxford Univ. Press.

"Silicon Processing, vol. 1", S. Wolf and R.N. Tauber, (Lattice Press).

Prerequisite:

The only prerequisites the students need are an understanding of basic transistor and diode operation. ENSC 222/ENSC 225 (Electronic Design I) or equivalent.

Lecture Schedule

Lecture Monday, Wednesday 17:30 - 18:50 pm, SCB8666

Week 1: Clean Room Technology and Silicon Wafer Production

• Basic outline of fabrication process: with to real structures.
• Theory behind clean room operations:
• History of semiconductor devices: diodes, transistors, Germanium/Silicon transition, monolithic integrated circuits
• Basic operation of Transistors, diodes
• Projected trends in Fabrication
• Theory and operations for contamination elimination, and safety issues.
• Silicon wafers; Crystallography, Production and Defects:
• Basic silicon wafer parameters, solid solubility of dopants in silicon, defects, and basic economics of operations.

Week 2: Thermal Oxidation

• Basic theory of the silicon oxidation, practical operations and measurement of films (thickness and quality).
• Tsupreme 4 simulation package introduction

Week 3: Lithography

• Basic operation of photolithography, chemical basis of photoresist, exposure equipment, exposure/development theory, and problems.

Week 4: Advanced Lithography

• Dealing with defects and exposure effects
• Advanced Lithography, Deep UV, Extreme UV, X-ray

Week 5: Etching

• Theory and operations of etching in general;
• wet (chemical) etching of oxides

Week 6: Etching II

• Wet etching of silicon and metals

Week 7: Diffusion Processes & Ion Implantation

• Diffusion theory (constant, limited source, multisource).
• Theory and operation of Ion implantation doping techniques.

Week 8: Thin Film Deposition: Evaporation and Sputtering

• Theoretical and experimental operation of vacuum systems.
• Theory and operation of evaporation and sputtering systems

Week 9: Thin Film Deposition: Chemical Vapor Deposition

• Theory and operation of Chemical Vapor Deposition (CVD), Plasma Enhanced CVD
• Film thickness measurement and film problems

Week 10: Expitaxy CVD and Dry Etching Processes

• Expitaxy (deposition with same crystal structure) & laser CVD
• dry etching processes (Plasma, Sputtering and Reactive Ion)

Week 11: Packaging, Yields, Processing Facility Setup and Silicon Foundries

• Testing, dicing of wafers, packaging, bonding, yield theory and measurements.
• Measurement techniques: Optical microscope, Scanning Electron Microscope, energy dispersive analysis of X-rays, Augue analysis, Secondary Ion Mass Spectroscopy (SIMS), Laser Ion Mass Spectroscopy (LIMS), Rutherford Backscatter Spectroscopy (RBS), X-ray diffraction.
• Silicon Foundries

Week 12: CMOS and Bipolar Process Integration in practice

• Layer by layer process of sample CMOS and Bipolar structures showing all the processes discussed taking place.
• Yield Analysis
• Using mask design tools

Week 13: Future of the processing & Project Presentations

• Problems in submicron technology and Micromachining/sensors as a new fabrication area.
• Presentations of student projects (Graduate Students)
• Summary of main course points.

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  Laboratory Section

Projects in Microfacation Lab (ASB 8823)

Students will work in 3-4 people teams which start with a bare silicon wafer and create finished IC's which include diodes, solar cells, transistors and some characterization test devices. All the process steps will be done by the students, who will also characterize the parameters for each step. Electrical characterization of the devices (diodes etc) will also be accomplished. Students get to keep samples of their own IC's.

Week 2: Tour of Microfabrication facilities (ASB 8823)

• Tour of the microfabrication facilities, inspection of chips under microscopes. Learning how to don clean room suits, gloves, handling wafers, use of tweezers,

Week 3: Demonstration of laboratory processes

• Demonstration of oxide growth: learning how to preoxidation clean wafers, run oxidation furnaces, control of flow values, insertion/withdrawal of wafers, and measure the oxides.

Week 3-5: Growth and patterning of oxide film on silicon.

• Set up furnace and grow oxide to stated thickness. Identify thickness of several sample wafers from their colour.
• Characterize grown film: measure thickness.
• Pattern the first oxide layer
• First Lab report done on this work

Week 6-13: Build simple 3 level structures:

• Build simple diffused diode, solar cells and test structures.
• Clean wafers, grow oxide, define oxide layers with photolithography.
• Do source/drain diffusion and measure results.
• Oxide regrowth, define gate area and grow gate oxide, measure thicknesses.
• Define contact cuts, etch oxide, inspect and measure contact size.
• Learn operation of simple sputter coater (thin film deposition).
• Deposit metal and measure thickness via profilometry.
• Deposit metal (contacts and gate), define/etch, measure thickness and line widths.
• Measure simple diode and transistor characteristics.
• Measure test devices: metal and diffusion sheet resistance, contact chains, plus C-V of gate oxide.

  Course Assignments and Tests

• Two Laboratory reports must be submitted.
• Students will be assigned a weekly problem set, including simulations of process steps.
• One mid term test (about week 6) and final examination after week 13

Graduate Students

Mark Distribution

Student receive the highest of the following distributions:

ENSC 495

• 30% laboratory reports, 20% problem assignments, 10% mid term, 40% final exam.
• 30% laboratory reports, 15% problem assignments, 55% final exam.

ENSC 851

• 30% lab reports, 15% Minor Project, 20% problem assignments, 10% mid term, 35% final exam.
• 15% lab reports, 45% Major Project, 20% problem assignments, 20% mid term.