Transcript Slide 1
Dilbert Dilbert Wal-Mart 9-8-2013 Apple Computer • • • • Started about the same time as Microsoft Was founded by Steve Jobs and Steve Wosniak in a garage in California’s silicon valley Was hardware focused vs. software focus for Microsoft Created the first personal computer Apple Computer • • • • Developed the point and click interface with a mouse Was nearly bankrupted by IBM style personal computers using Microsoft software Refused to interface with Microsoft software Steve Jobs was forced out of the company Apple Computer • • • • Company nearly failed Steve Jobs rejoined Focused on high quality innovative devices Developed iPod • • iTunes created as a way to get value for music and replace free downloads Developed iPhone • Many versions with innovative technology Apple Computer • Developed iPAD • • • • • Opened tablet computer market Developed iPad mini Surpassed Microsoft in value Is now the most valuable company in the World Can Apple continue to develop new technology and devices? Materials Conductive materials – valence band overlaps the conduction band Non conductive materials – valence band is separated from conduction band and electrons can not easily get to the conduction band Semiconductor materials – conduction band is close to valence band and electrons can easily jump from the valence band to the conduction band with an energy source Silicon Silicon is an element Silicon is the first or second most abundant element on the earth Sand is a form of silicon Silicon is know as a semiconductor because under certain conditions it can conduct electricity (electrons) Silicon is the most widely used material for today’s microelectronics Silicon was not the first semiconductor material used, germanium was first. silicon Raw silicon is melted and grown into a single crystal ingot Silicon ingot being grown Completed silicon ingot Once the ingot is complete, wafers are sawn from the ingot and the top side is polished to a mirror finish The size of the silicon wafers has increased Starting with 1 inch diameter wafers Larger wafers provide more chips per wafer with the same labor cost although equipment costs are higher Today 12 inch diameter wafers are common Group 4 Silicon From the periodic chart you can see that silicon is a group 4 element Group 4 elements have 4 electrons in their outer most electron shell Germanium is also a group 4 element Why is silicon an excellent microelectronics material? 1. 2. 3. 4. 5. It is very abundant It can be grown into a single orientation crystal It can be made electrically active easily It can be made to conduct electrons with a small applied potential It has a naturally forming oxide that acts as an insulating and diffusion barrier Two dimensional schematic of three dimensional crystal Group 3 Elements P type doping – Positive, electron short, also called a hole Group 5 elements N-type doping – N is negative, electron rich Combing n-type silicon and ptype silicon gives a pn junction The EE project in the clean room will use silicon wafers as the base for the antennas Special tweezers are used to handle silicon wafers The future • • • • Silicon will continue to play a dominant role but other semiconductor materials will play an increasing role III-V semiconductor materials made from group III and group V elements are now common ( GaAs, InP, AlN ) II-VI semiconductor materials are being investigated for special applications SiC, “diamond like carbon”, and SiGe are also of interest Next 2 homework assignments • • • • • • • HW5 and HW6 from the web site Write a one page report on “RFID” and “GPS” Be sure to include the frequency of operation for “RFID” and “GPS” Know what “RFID” stands for and the two types of GPS Know what GPS stands for Include at least two references for each paper Both are due next class meeting