Alternative materials and fabrication techniques Applications in biology and chemistry Applications in medicine A real MTL example of rapid prototyping

Closed book Covers lecture materials covered in problem sets through lithography Five questions, 20 pts. each a formula sheet will be provided a Sample quizzes from previous terms and the formula sheet are on the course web site Spring 2003 -Prepared by C. ross

The lithographic Process a BasIc process Definitions Fundamentals of Exposure Exposure Systems Resists Advanced Lithography Recommended reading Plummer, chapter 5

We saw how dopants were introduced into a wafer by using diffusion (predepositionanddrive-in') This process is limited cannot exceed solid solubility of dopant -difficult to achieve light dopin Ion implantation is preferred because controlled, low or high dose can be

Doping and diffusion I Motivation Faster MOSFET requires Requires shallower source, drain Ar P* poly snorter channel

Microelectronics letters journals IEEE Electron Device letters Applied physics Letters Available online at libraries mit edu Click on vera (Virtual Electronic Resource Access)

Review of process Structures to be tested Sheet resistance MOS Capacitor Fall 2003-MA schmidt

Why spend a whole lecture on oxidation of Si? Ge has high ue, Wh, Ge stable but no oxide GaAs has high ue and direct band Why sio? Sio, is stable down to 10 9 Torr. T>900C Sio can be etched with hf which leaves si unaffected

Processes: gift of Slo2-Expose Si to steam = uniform insulating layer or metal film growth: high vacuum, single element Contrast with CVD: toxic, corrosive gas flowing through valves

What does Materials Science have to do with Microelectronic Processing? Need to understand DIfferences: metals, oxides and semiconductors Atomic bonding Oxidation rates