A Trumpf pulsed CO2 laser system has helped to bring extreme ultraviolet lithography to the integrated circuit production line.
The pulsed CO2 laser system has five amplifier stages. These stages boost an initial pulse of a few watts by a factor of 10,000 to 20kW of mean pulse power. The peak pulse power is measured at several megawatts. Since spring 2012 Trumpf has provided such systems to its unnamed customers. The system has been used to image structural elements only 13.8nm high.
For profitable EUV manufacturing the workpiece requires 50,000 hits per second. The Trumpf system achieves this by using laser produced plasma. Tin drips into a vacuum chamber and a flash of laser light strikes the tin drop and ionises it. This ionisation leads to a flash of EUV light at the wavelength needed, 13.5nm.
This pulsed CO2 laser system will mean that Moore’s law, the theory that microelectronics double in computational power and halve in cost every two years, can continue. Semiconductor production lines have typically used 193nm lithography systems to produce integrated circuits with 22nm structures. With EUV radiation at 13.5nm, structures smaller than 10nm can be achieved to fabricate the next generation of microchip.