Basic Transistor Physics

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The first transistor was demonstrated on Dec. 23, 1947, at Bell Labs by William Shockley. This new invention consisting of P type and N type semiconductive materials (in this case germanium) has completely revolutionized electronics. Transistors quickly replaced vacuum tubes in almost all applications (most notably those in discrete logic). Today when we think of transistors the first thing that comes to mind is computers. Advances in transistor technology and manufacturing processes as well as new materials being used for the semiconductor matrix and wiring have led to smaller, faster, cheaper, lower power transistors. Some of the basic principles behind semiconductor behavior and the restrictions currently faced by modern transistors will be discussed in the following pages.

Transistors are composed of a P type (positively doped) and N type (negatively doped) semiconductor material. These P-N junctions are the heart of both BJTs (Bipolar Junction Transistors) and FETs (Field Effect Transistors). BJTs have a physical connection between they current controlling input (base) and the input and output (collector and emitter). This results in a trickle current into the base. FETs have a physical separation between the control (gate) and the input and output (drain and source).

BJT and FET transistors are used in virtually every electronic device requiring current regulation or amplification. They make it very easy to precisely control power to a device reliably and with much greater efficiency than other methods. Another common use of transistors is their role in discrete logic. First used in DTL (Diode Transistor Logic) transistors compact nature and high switching speeds lend themselves well to use in logic ICs. In ...

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...er clock speed operation than the G4 processor and will include all the latest fabrication developments when released. Processor core voltage for this chip will be as low as 1.2v allowing a higher transistor count with very low power dissipation. Pentium 4 core voltage is in the range of 1.55v.

Smaller, faster, cheaper...transistors aren't quite as boring as you thought huh?

Bibliography

1. IBM Copper Technoglogy http://www.chips.ibm.com/

2. AMD http://www.amd.com/

3. Intel Semiconductor Technology http://www.intel.com/

4. Motorola PowerPC Division http://www.motorola.com/

5. Transistor History 101 http://users.arczip.com/rmcgarra1/xstrhist.html

6. Britney's Guide to Semiconductor Physics http://britneyspears.ac/lasers.htm

7. The Mac Address http://www.themacaddress.com/

8. Electromigration http://www.ifw-dresden.de/ifs/31/gfa/em_e.htm

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