INTRODUCTION
The pace of semiconductor materials and device development has been staggering, and the
impact on human society monumental. Leading this advance has been the development of the
silicon-based MOSFET device and its continuous high level of integration. Moore’s Law (shown
in figure .1), which predicts the doubling of device density every 18 months, has been the gov-
erning maxim of the industry. Sustaining Moore’s Law has required:
- The development of lithography tools to achieve the 45 nm gate length MOSFETs released
into production in 2006 - The continuous scaling of silicon wafers to 12 inch diameters (2005) and 15 inch in the
future to enable large chip yields per wafer - Tremendous advances in interconnect technology
- Device innovations to continuously maintain charge control and low gate leakage as the
oxide thickness is scaled down along with the gate length
Though most of the chip and dollar volume of the industry has been driven by Si-based CMOS
architecture, there have been critical advances made in other semiconductor technologies. The
ability to grow epitaxial layers in a controlled fashion, initially by Liquid Phase Expitaxy (LPE)
and Vapor Phase Epitaxy (VPE) and currently by Metalorganic Vapor Phase Epitaxy (MOVPE)
and Molecular Beam Epitaxy (MBE), has enabled the compound semiconductor industry to
mature into a small but critical component of the total space. The impact has been felt in both the
electronics and photonics arenas. In the former, development of the Heterojunction Field Effect
Transistor (HFET) and the Heterojunction Bipolar Transistor (HBT) has had a large impact on
analog and mixed signal applications. In the low noise receiver area, GaAs and InP based HFETs
are the preferred technology. The GaAs-based HBT is preferred for power amplifiers in cellular
phones. The Si/SiGe HBT is being actively used in mixed signal applications such as A/D
converters and in BiCMOS implementations.
In the optical arena, the development of Light Emitting Diodes (LEDs), lasers, and detectors
has been profound. LEDs are used in prolific applications such as signage displays and remote
controls as well as in communication devices. The advent of GaN-based LEDs has raised the
possibility of a revolutionary advance in lighting with the emergence of solid-state lighting.
xx