Resources Contact Us Home
Laser spectral engineering for lithographic process

Image Number 16 for United States Patent #6671294.

An integrated circuit lithography technique called spectral engineering by Applicants, for bandwidth control of an electric discharge laser. In a preferred process, a computer model is used to model lithographic parameters to determine a desired laser spectrum needed to produce a desired lithographic result. A fast responding tuning mechanism is then used to adjust center wavelength of laser pulses in a burst of pulses to achieve an integrated spectrum for the burst of pulses approximating the desired laser spectrum. The laser beam bandwidth is controlled to produce an effective beam spectrum having at least two spectral peaks in order to produce improved pattern resolution in photo resist film. Line narrowing equipment is provided having at least one piezoelectric drive and a fast bandwidth detection control system having a time response of less than about 2.0 millisecond. In a preferred embodiment, a wavelength tuning mirror is dithered at dither rates of more than 500 dithers per second in phase with the repetition rate of the laser. In one case, the piezoelectric drive was driven with a square wave signal and in a second case it was driven with a sine wave signal. In another embodiment, the maximum displacement was matched on a one-to-one basis with the laser pulses in order to produce a desired average spectrum with two peaks for a series of laser pulses. Other preferred embodiments utilize three separate wavelength tuning positions producing a spectrum with three separate peaks.

  Recently Added Patents
Die seal ring
Organic metal complex and its use in organic electroluminescent device
Automated synchronization of design features in disparate code components using type differencing
Telephone line seizure module
Active pulse blood constituent monitoring
Electronic multiparty accounts receivable and accounts payable system
  Randomly Featured Patents
Integrated galvanomagnetic sensor array system
Multiple external control actuator for electronic demand register
Squeakless funiture spring anchor clip and method of making same
Method for manufacturing an aluminum die cast piston for reciprocating compressors
Techniques for producing a consistent copy of source data at a target
Butt joined electrical apparatus and module
Tubing bend for pneumatic conveying system
Encapsulating a substrate
Universal event/data recorder system
In-press process for coating composite substrates