SAN JOSE, USA: Ultratech Inc., a leading supplier of lithography and laser-processing systems used to manufacture semiconductor devices and high-brightness LEDs (HB-LEDs), announced the release of its new field-tested LSA101 laser spike annealing (LSA) system, which enables critical millisecond annealing applications for the 28-nm node and beyond.
The LSA101 features a new, state-of-the-art design of coherent optics, which generates a longer, more focused laser beam at the wafer plane, providing the capability to increase throughput by approximately 200 percent compared to its predecessor, the LSA100A. This dramatic improvement in throughput gives a corresponding approximate 65 percent reduction in cost of ownership.
The LSA101 also extends the ability to decrease the annealing time by approximately a factor of two compared to the LSA100A, which has been demonstrated to be critical for stress reduction in advanced technology nodes where many IC manufacturers are using aggressive strain engineering. Currently, the LSA101 is being qualified for 28-nm production by a customer in Asia.
"The LSA101 is based on the same field-proven, long-wavelength technology as its predecessor, the LSA100A, and it delivers the same inherent advantages for advanced CMOS manufacturing, such as superior within-die uniformity, layout-independent process results, and closed-loop wafer temperature control," noted Jeff Hebb, Ph.D., vice president of laser product marketing at Ultratech.
"With the LSA101, we are able to deliver this performance at a much lower cost of ownership. With the improvements in beam length and dwell time reduction, the system delivers a standard throughput of 35wph. In addition, the LSA101 can also be operated in "optimal throughput" mode, where the wafer is annealed with half as many laser scans with only a modest impact on within-wafer uniformity. In this mode, the tool delivers an enhanced throughput of 60wph, the highest in the industry for millisecond annealing tools."
The LSA101 also has a wider operating range for annealing time, or dwell time, which is critical for stress management in advanced devices. The LSA101 has a minimum dwell time of 200 microseconds compared to 400 microseconds of the LSA100A.
Hebb explained: "It is a well-established phenomenon that wafer warpage and lithography overlay errors are reduced at shorter dwell times. As device dimensions shrink, overlay requirements are getting more stringent and customers are getting more aggressive with strain engineering to enable high channel mobility. The reduced dwell time capability allows our customers to maintain high processing temperatures for such devices without suffering yield loss due to overlay errors. As a result, this capability provides improved device performance and lower leakage.
"The LSA101 process matches the device performance of the previous LSA models. Overall, the LSA101 system is an example of Ultratech's commitment to continue to develop advanced technology systems that provide competitive and economic advantages for its global customers."