Why do we need metallization?- To connect devices electrically to each other and to the outside world; power and data Local interconnect doped polySi, silicides Packaging

lasma enhanced surface diffusion without need for Dry etching Momentum transfer from plasma to remove surface species e We will see evaporation: Evaporate

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