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Method of monitoring status of a silicon layer by detecting, emission spectra variable during ectching
1048
New patents
4430719 CALCINATION CONTROL SYSTEM Robert M Pearson assigned to Aluminum dz Chemical Corporation
Kaiser
A frequency-spectrum analyzer with phase-lock for analyzing the frequency and amplitude of an input signal is comprised of a voltage controlled oscillator (VCO) which is driven by a ramp generator, and a phase error detector circuit. The phase error detector circuit measures the difference in phase between the VCO and the input signal, and drives the VCO locking it in phase momentarily with the input signal. The input signal and the output of the VCO are fed into a correlator which transfers the input signal to a frequency domain, while providing an accurate absolute amplitude measurement of each frequency component of the input signal.
4430151 Nuclear magnetic resonance (nmr) is employed for the control of heat-input or feed rate of calcination and/or drying facilities. The residual volatile material content of the heat-treated material is monitored by nmr and the results obtained from the monitoring are employed to adjust the heat-input or feed rate to avoid overdrying or calcining of the heat-treated material. A computer, such as a microprocessor, may be utilized in combination with the nmr apparatus to provide instantaneous process control.
METHOD OF MONITORING STATUS OF A SILICON LAYER BY DETECTING, EMISSION SPECTRA VARIABLE DURING ETCHING Tsutom Tsukada, Tokyo, Anelva Corporation
Japan
assigned to
4430611 FREQUENCY SPECTRUM ANALYZER WITH PHASE-LOCK Thomas Boland assigned to The United States of America as represented by the United States Department of Energy
In a monitoring method of monitoring status of a silicon layer etched in a hollow space by plasma, a chlorine including gas is introduced into a hollow space to cause Ccl-radical to occur in the hollow space. A first spectrum region is selected to detect first emission spectra of the Ccl-radical which are variable in intensity only during the etching and which may include a wavelength of 307 nm. Preferably, a second spectrum region is selected to second emission spectra invariable even during the etching and to indicate the beginning and the end of the etching by monitoring a relationship between the first and the second emission spectra. The second spectrum region may include a wavelength of 396 nm. Alternatively, emission spectra of OHradical which results from water remaining in the hollow space may be monitored as the first emission spectra.
New patents
4430719 CALCINATION CONTROL SYSTEM Robert M Pearson assigned to Aluminum dz Chemical Corporation
Kaiser
A frequency-spectrum analyzer with phase-lock for analyzing the frequency and amplitude of an input signal is comprised of a voltage controlled oscillator (VCO) which is driven by a ramp generator, and a phase error detector circuit. The phase error detector circuit measures the difference in phase between the VCO and the input signal, and drives the VCO locking it in phase momentarily with the input signal. The input signal and the output of the VCO are fed into a correlator which transfers the input signal to a frequency domain, while providing an accurate absolute amplitude measurement of each frequency component of the input signal.
4430151 Nuclear magnetic resonance (nmr) is employed for the control of heat-input or feed rate of calcination and/or drying facilities. The residual volatile material content of the heat-treated material is monitored by nmr and the results obtained from the monitoring are employed to adjust the heat-input or feed rate to avoid overdrying or calcining of the heat-treated material. A computer, such as a microprocessor, may be utilized in combination with the nmr apparatus to provide instantaneous process control.
METHOD OF MONITORING STATUS OF A SILICON LAYER BY DETECTING, EMISSION SPECTRA VARIABLE DURING ETCHING Tsutom Tsukada, Tokyo, Anelva Corporation
Japan
assigned to
4430611 FREQUENCY SPECTRUM ANALYZER WITH PHASE-LOCK Thomas Boland assigned to The United States of America as represented by the United States Department of Energy
In a monitoring method of monitoring status of a silicon layer etched in a hollow space by plasma, a chlorine including gas is introduced into a hollow space to cause Ccl-radical to occur in the hollow space. A first spectrum region is selected to detect first emission spectra of the Ccl-radical which are variable in intensity only during the etching and which may include a wavelength of 307 nm. Preferably, a second spectrum region is selected to second emission spectra invariable even during the etching and to indicate the beginning and the end of the etching by monitoring a relationship between the first and the second emission spectra. The second spectrum region may include a wavelength of 396 nm. Alternatively, emission spectra of OHradical which results from water remaining in the hollow space may be monitored as the first emission spectra.