The semiconductor industry reaches an important milestone on the path to producing 10GHz chips.
The Extreme Ultraviolet LLC, a joint development effort charged with developing next-generation chip-manufacturing technology, recently built its first chip-manufacturing machine using the extreme ultraviolet lithography (EUV) process.
Known as the EUV engineering test stand, the device is the first piece of test equipment for what is expected to be a new line of chip-manufacturing machines capable of producing processors running at 10GHz and faster. The fastest PC processors today top out just above 1GHz.
EUV LLC will spend the next several months testing the machine and then take the first steps toward test manufacturing by using the device to print images on silicon wafers.
This type of lithography, known as photolithography, works much like taking a picture. A machine is used to print an image of a circuit on a silicon wafer, those images are developed, and then materials are removed or deposited, layer by layer.
Advances such as this with next-generation lithography processes are vital to chipmakers such as Intel and Advanced Micro Devices, as EUV is the method by which they plan to continue boosting chip speeds in coming years.
Upholding Moore's Law
"There's a wall that you run into with conventional lithography," said Chris Philippi, business manager for the EUV LLC. "(EUV) is a major breakthrough in keeping us in line with Moore's Law."
Moore's Law, formulated by Intel co-founder Gordon Moore, states that the number of transistors a chip can hold will double every 18 to 24 months, as transistor size shrinks. More transistors, which switch off and on to represent binary data, lead to a corresponding leap in performance.
The lithography technique now used, called deep ultraviolet, will suffice for one or two more generations of manufacturing processes, down to chip features the size of 100 nanometers, or one-tenth of a micron. Chipmakers are working on switching to 0.13-micron processes.
As chipmakers reduce sizes below 100 nanometers, a new lithography technology will be needed--because as chip features decrease in size, the wavelength of light used in the lithography process must also be decreased. Deep ultraviolet lithography uses a wavelength of 240 nanometers. EUV uses a much shorter wavelength.
Without a next-generation lithography technology like EUV, chip manufacturers, including AMD and Intel would hit a wall in 2004 or 2005, where they would be unable to produce faster chips.
The EUV LLC is a coalition that includes researchers from the Lawrence Livermore and Sandia national laboratories, along with chipmakers Intel, AMD, Micron Technologies and Infineon Technologies. Other companies may soon join.
The EUV LLC expects to use the first test stand to test and fine-tune the EUV process.
First images by April
"We expect to have the first full field-scanned images by April 1," said Chuck Gwyn, program director for EUV at the Lawrence Livermore National Laboratory in Livermore, Calif.
"We will continue working on developing that tool throughout the next year," he said.
With testing finished sometime in 2002, the EUV LLC expects beta manufacturing tools to be produced late in 2003 and final manufacturing tools to appear in 2005, Gwyn said.
Intel expects to use EUV to manufacture new transistor designs it says could hit speeds up to 10GHz.
The EUV LLC is working simultaneously with chip-equipment manufacturers such as the Silicon Valley Group and ASM Lithography Holdings. Its goal is to decrease the amount of time necessary to get EUV into commercially available manufacturing equipment.
The first such equipment will be used to manufacture chips with features at the 70 nanometer (0.07 micron) size, about a thousand times smaller than the width of a human hair.
Current desktop chips, such as Pentium III or Athlon chips, are manufactured at 180 nanometers.
To the end of silicon
"EUV technology is very extendable...and we have demonstrated that it would work down to the 30 nanometer level," Gwyn said.
Barring a new invention, which is always possible, "It should take us to the end of silicon...as we know it today," he said.
Analysts say EUV is the front-runner among competing next-generation manufacturing processes.
"EUV looks like it's moving along well and building momentum," said Linley Gwennap, principal at the Linley Group, a Mountain View, Calif., market research firm.
A technology known as electron beam lithography, or e-beam, is also in development by a number of companies, including IBM.
E-beam works much differently than EUV, relying on a beam of electrons to draw individual transistors on a chip during the manufacturing process. The EUV process draws an entire layer of a chip at one swipe.
"The challenge for e-beam was always trying to figure out how to scale production. EUV obviously has challenges as well...but at least they (EUV LLC) have a good handle on how to solve the problems," Gwennap, said.
The EUV LLC contests that its way is the only way to keep up with Moore's law and meet chip production needs.
Throughput on EUV is targeted to be 80 wafers per hour on 300-millimeter wafers. That's about what companies get today on standard 200-millimeter wafers.
Currently, e-beam technology is much slower, with throughput closer to one wafer per hour. However, development continues in several areas, including the e-beam project inside chip powerhouse IBM.
An effort to create a company around scalpel electron-beam projection lithography (EPL) collapsed, according to reports in EE Times, a trade magazine that tracks the semiconductor industry.
"I think three or four years ago there was a lot of concern over whether EUV would work at all," Gwennap said. "But now it looks to be the more manufacturable technology."