semiconductor switching speeds

Discussion in 'Homework Help' started by ninjaman, Jun 17, 2014.

  1. ninjaman

    Thread Starter Member

    May 18, 2013

    I have to do a report on semiconductors but im having a hard time finding anything that makes sense and is to the point and gives me information to match the criteria of the report. one of the questions is

    Describe factors limiting switching speed of modern semiconductors, including smallest obtainable transistor size and minimum photoresist width and describe design changes that can be made to enhance overall switching speed and the effects on other performance characteristics of making these changes, such as effects on chip and wafer sizes

    could someone please give me a hint as the information that I find doesn't seem to make sense or explain what im looking for. I have chosen cmos as a subject. though I have found information about heterojunction transistors and that they are the fastest. but I cant find information about the smallest photoresist size. i have found some information titled "roadmap to 22nm and beyond". this explains some things about the "xxnm" sizing but its out of date by about four years. should this matter? I cant find anything recent. I have read about double gate fets and the fact they cut down on leakage current and another type of fet. I have looked for mosfets and their construction. I know that the gate length has something to do with it as well as width. im guessing the minimum photoresist is the part that forms the gate. this being a size like 22nm. a narrow gate would provide faster electron travel? but I don't know of any where that could explain this a little better.
    also, design rules? what would I change to improve things?
    does anyone know of a web site, that's all im asking! a hint! (we can play sherades if you find that fun, how many syllables, is it a book or a movie?)

    anyway this is the last part of my assignment and im done. I have searched abunch of things and found very little to provide an answer.
    if you could offer some tips for searching that would be a big help. so far I have tried combinations of the following. factors limiting switching speeds in cmos, circuits, pcbs, transistors, mosfets, what affects switching speeds, how cmos, mosfets are made construction process, manufacture process

    thanks, enjoy summer!
  2. Veracohr

    Distinguished Member

    Jan 3, 2011
    The higher the switching speed, the more current is needed, which determines minimum transistor and current path specs. Also, transistors (especially FETs) have input and output capacitance, which affects circuit speed. Those are the biggest factors I can think of off the top of my head.