Damage formation and annealing studies of low energy ion implants ...

Number of transistors
10 9
10 8
10 7
10 6
10 5
10 4
10 3
4004 8008
Intel386 processor
8080
Intel286
8086
Intel486 processor
Intel® Itanium® 2 processor (9MB cache)
Intel® Pentium® processor
Intel® Pentium® III processor
Intel® Pentium® II processor
1970 1975 1980 1985 1990 1995 2000 2005
Year
To continually achieve this rate of improvement, aggressive targets for the
performance of all aspects of devices, including the gate length, junction depth, and
sheet resistance, as well as production methods have been laid out as a guide in the
International Technology Roadmap for Semiconductors (ITRS) (13). This states
performance criteria and designates technology nodes, determined by the repeat spacing
of devices, which are considered necessary for the industry to be able to achieve on an
annual basis in order to sustain the rate of progress of “Moores Law”. The roadmap
pushes research and development to achieve these criteria, particularly where no
manufacturable solutions are known. The current version of the roadmap contains
detailed short term goals till 2009 and longer term projections till 2018.
Simply reducing the gate length alone would produce short channel effects. This
situation arises when the depletion widths of the source and drain become comparable
to the channel length and merge, known as “punch through”, and the device no longer
operates with MOSFET characteristics. This behaviour can short the channel and
increase subthreshold leakage currents from the source to the drain (2-4). For this reason
transistor dimensions have to be generally reduced by scaling down all dimensions and
keeping the same transistor shape. ‘Halo’ or ‘pocket’ implants place dopants just below
5
Intel® Itanium® 2 processor
Intel® Pentium® 4 processor
Figure 1.2 Number of transistors on Intel Microprocessors. Values from (12)