Abstract: A method is provided of making a photoemissive cathode including bonding an electron emissive layer to a glass faceplate at an elevated temperature and pressure to form a cathode structure and cooling the cathode structure at a rate which will maintain stress between the electron emissive layer and the faceplate at or below a predetermined level in order to avoid brush marks and crosshatchings during subsequent processing steps. The cathode is cooled from a bonding temperature to room temperature in approximately twenty minutes or less.

Abstract: A method for sensitive and precise determination of the temperature of a thin layer or wafer of bandgap material, without requiring contact to the layer or to the wafer, is based on selection of optical wavelength or wavelengths and the measurements of transmittance through the sample at such wavelength(s). The relationship between the temperature variations of the absorption coefficient, whether determined by band-to-band absorption or a totally different mechanism, and the measured transmittance, provide an indication of the sample temperature, without regard to the ambient temperature. The method prescribes how to select the wavelength(s) based both on the intrinsic properties of the material and on the practical considerations of the measurement situation.

Abstract: A method of accurately determining the temperature of a thin layer of bandgap material without requiring contact to the layer involves the use of optical radiation through the layer and the detection of optical absorption by the layer. The relationship between the temperature varying bandgap energy and the resulting optical absorption characteristics provides an indication of temperature independent of ambient temperature. Apparatus for performing high quality temperature detection and control is also provided.

Abstract: A method of accurately determining the temperature of a thin layer of bandgap material without requiring contact to the layer involves the use of optical radiation through the layer and the detection of optical absorption by the layer. The relationship between the temperature varying bandgap energy and the resulting optical absorption characteristics provides an indication of temperature independent of ambient temperature. Apparatus for performing high quality temperature detection and control is also provided.

Abstract: A method of accurately determining the temperature of a thin layer of bandgap material without requiring contact to the layer involves the use of optical radiation reflected off the bandgap material and the detection of the reflected energy. The relationship between the temperature varying bandgap energy and the resulting reflection characteristics provides an indication of temperature, independent of ambient temperature.

Abstract: An apparatus for heat cleaning a semiconductor material by producing a uniform thermal distribution in the area of the material being cleaned. In one arrangement a heater block is positioned between a lamp nad a photocathode. The semiconductor material layer of the photocathode is directed away from the lamp. The heater block absorbs the entire range of wavelengths radiated by the lamp but reradiates only long wavelengths to the photocathode. In another arrangement, a laser has its beam directed to a focusing and scanning system. The resultant beam is directed to a photocathode which is positioned with its semiconductive layer directed toward the beam.

Abstract: A method of accurately determining the temperature of a thin layer of bandgap material without requiring contact to the layer involves the use of optical radiation through the layer and the detection of optical absorption by the layer. The relationship between the temperature varying bandgap energy and the resulting optical absorption characteristics provides an indication of temperature independent of ambient temperature. Apparatus for performing high quality temperature detection and control is also provided.

Abstract: A method of determing the actual temperature of a layer of an infrared material, especially during heat cleaning, which includes measuring the thickness of the layer and the amount of radiation being emitted from it. An apparent temperature corresponding to a desired actual temperature is found from a curve of apparent temperature, which are derived from the radiation amount, versus thickness. The apparent temperature which corresponds to the desired actual temperature compensates for interference effects on the radiation measurement. A computer may be utilized to calculated the apparent temperature which corresponds to the desired actual temperature and to regulate and maintain the infrared material at the apparent temperature.