Abstract: A new confocal microscope and a new device fabrication method in which linewidth control is achieved using the new confocal microscope are disclosed. This new confocal microscope has a configuration which achieves multiple passes, e.g., three, four, five, six, seven or more passes, of the incident light through the objective lens of the microscope. As a consequence, the new confocal microscope exhibits a smaller effective depth of focus and a smaller effective resolution than a conventional confocal microscope.

Abstract: A new technique for forming non-rectifying electrical contacts to III-V semiconductor materials, without the use of dopants or of an alloying procedure, is disclosed. In accordance with this technique, an electrical contact is formed simply by depositing a region of material (onto the semiconductor material) having a composition which includes at least one metal element and at least one of three specific Group V elements, i.e., P, As, or Sb, and having a bulk electrical resistivity equal to or less than about 250 .mu..OMEGA.-cm. Alternatively, a contact is formed by depositing nickel, or a nickel-containing material essentially free of gold and silver, and having a composition which does not include any of the three Group V elements. The nickel, or nickel-containing material, is then reacted with the substrate to form a compound having a composition which includes nickel as well as one of the three Group V elements.

Abstract: A new confocal microscope and a new device fabrication method in which linewidth control is achieved using the new confocal microscope are disclosed. This new confocal microscope has a configuration which achieves multiple passes, e.g., three, four, five, six, seven or more passes, of the incident light through the objective lens of the microscope. As a consequence, the new confocal microscope exhibits a smaller effective depth of focus and a smaller effective resolution than a conventional confocal microscope.

Abstract: A deep-UV step-and-repeat photolithography system includes a narrow-bandwidth pulsed excimer laser illumination source and an all-fused-silica lens assembly. The system is capable ofline definition at the 0.5-micrometer level. One significant feature of the system is its ability to perform wafer focus tracking by simply changing the frequency of the laser.

Abstract: An optical system is disclosed which includes at least a first source of electromagnetic radiation (signal beam radiation), a device for processing the signal beam radiation, and a detector for detecting the processed signal beam radiation. The processing device functions, for example, as an amplitude modulator, a demultiplexer, or a switch, and includes a material region exhibiting a nonlinear optical response at one or more resonant wavelengths of electromagnetic radiation, as well as at least a second source of electromagnetic radiation (control beam radiation) for selectively inducing the nonlinear optical response. Significantly, the wavelength, duration and intensity of the control beam radiation are chosen to induce a resonant, nonlinear optical response, essentially free of any relatively slow component, in said material region at repetition rates higher than about 1.25.times.10.sup.4 Hz, or higher than about 3.3.times.10.sup.10 Hz, or even as high, or higher, than about 2.5.times.10.sup.11 Hz.