Moore's law predicts a 70 percent reduction in the size of the integrated circuit's features at every technology node. One dimension of interest (besides the gate length of the transistor) is the minimum spacing between interconnect lines. This dimension determines how densely packed the logic gates will be and ultimately how many transistors can fit on a single chip. We plotted (Figure 1 online) the minimum interconnect line pitch for all three manufacturers as a function of the technology node. All three players had comparable critical dimensions, illustrating that Moore's law is alive and well with no sign of slowing.
Interestingly, TSMC has slightly smaller dimensions than the two other manufacturers, probably because TSMC's customers are mainly SoC manufacturers, such as graphics processor and FPGA makers. With the latest graphics processors having more than a billion transistors, any reduction in chip size is highly beneficial to foundry clients, even though the individual transistors may not be as fast as Intel's or AMD's.
Every new technology node both reduces critical dimensions and improves process. Two fundamental process innovations being adopted by the main semiconductor companies are embedded silicon-germanium source/drain regions (eSiGe) and high-k metal gate technology (HKMG). eSiGe increases the performance of the slower type of transistors (PMOS), while HKMG helps the transistors switch faster and reduces the gate leakage.
Table 2 illustrates when these features were adopted by the three manufacturers. Here, Intel clearly shows leadership in implementing process innovations, having introduced eSiGe first at the 90nm node in 2004. AMD closely follows by one technology node, while TSMC is approximately two generations behind Intel (technically one and a half nodes behind in the case of HKMG since the 28nm node will represent a half-node). Advanced process features, such as silicon-on-insulator (SOI) used by AMD, were not compared if not widely adopted.
In the end, a better process technology does not guarantee a better semiconductor. In the past, AMD mitigated the lag in process and gained market share from Intel by making sound circuit design decisions such as having an efficient, short pipeline architecture and the first integrated memory controller on-die (later implemented by Intel). Intel is also facing tough competition in other market segments such as graphics processing and in the fast-growing ultra-low-power device market. However, assuming comparable designs, Intel's technology lead will likely allow it to have an edge over the competition, at least until the introduction of the 32nm technology from AMD/GlobalFoundries in late 2010 or early 2011.
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Carl Wintgens is senior process analyst at Semiconductor Insights, which specializes in analyzing semiconductors.