Trek, Inc.

Tokyo Shibaura Electric Co., Ltd.

Other

Shinko Electric Industries Co., Ltd.

Nippon Tungsten Co., Ltd.

Japan Fine Ceramics Center

Trek Holding Co., Ltd.

Toshio Uehara

Bruce T Williams

Hiroyuki Mizutani

Katsuji Nakagawa

Manabu Tani

Akiyoshi Itoh

Hideaki Matsubara

Peter McAnn

Norio Shiraiwa

Koki Tamagawa

Mitsuyoshi Nagano

Naoki Kawashima

Hiroaki Yanagida

Yoshiki Okuhara

Tadayoshi Yoshikawa

Miki Saito

Tamon Inouye

Jerzy Kieres

Tetsushi Matsuda

Kouta Tsutsumi

Shoji Aoki

Donnie Herman

A clamping system and a method of clamping a work piece are disclosed. The clamping system has an electrostatic clamp and a high-impedance voltmeter ('HIV'). The electro-static clamp may include a platen and a plurality of electrodes embedded in the platen. In use, at least some of the embedded electrodes provide one side of a capacitor and a work piece provides another side of the capacitor in order to hold the work piece relative to the platen when at least some of the embedded electrodes are electrically charged. The HIV is electrically connected to at least some of the embedded electrodes.

System and method for clamping a work piece

A dielectric layer for an electrostatic chuck is formed of a ceramic material having a first phase including aluminum oxide and a second phase including composite carbonitride (Ti, Me)(C, N) that contains titanium as fine grains. The Me represents a transition element and metals of Group 4 to Group 6 such as Mo and W. The ceramic material that includes the second phase by 0.05 vol % to 2.5 vol % has a volume resistivity value of about 10to 10(&#x3a9;&#xb7;cm) necessary for a Johnsen-Rahbek type electrostatic chuck.

Dielectric layer for electrostatic chuck and electrostatic chuck

A system which may be used to control, monitor and optimize an electrostatic clamp is disclosed. In one embodiment of the invention, there is a computer, a control circuit, and at least one amplifier. Also, a signal assessing circuit may be included and used to provide a sensing signal to an output signal of the control circuit. The signal assessing circuit may provide a sensing signal that can be used to monitor the capacitance of the electrostatic clamp. Further, the signal assessing circuit may include circuitry which monitors performance of the electrostatic clamp, and provide performance information to the control circuit.

Electrostatic clamp optimizer

A platen for electrostatic wafer clamping apparatus comprising a platen body of dielectric material and grains of electrically conductive material diffused in the dielectric material so that the platen has a relatively large electrostatic capacitance due to the diffusion of the conductive grains with the result that the platen provides an increased clamping force regardless of humidity. In accordance with another aspect of the invention, the thickness of the platen body can be decreased by an amount sufficient to maintain a constant clamping force with reduced applied voltage, to eliminate any residual voltage on the platen and to increase the speed of wafer release. The grains of electrically conductive material are present in an amount of from about 2.5 percent to about 15.0 percent of the volume of the platen body, and the grains of electrically conductive material are selected from the group consisting of carbonated transition metals, nitrified transition metals and carbonated grains. The dielectric material preferably is Al O , and the grains of electrically conductive material preferably are TiC and preferably in an amount of about 5% of the volume of the platen.

Platen for electrostatic wafer clamping apparatus

A sensor for an electrostatic detector including an elongated vibratory element supported at a mechanical node at one end in the manner of a cantilever beam, a sensitive electrode on the vibratory element near the other end and adapted to be disposed toward an electrical charge, field or potential being measured, and a driver transducer on the vibratory element for vibrating the element in a direction to vary the capacitive coupling between the electrode and the electrical charge, field or potential being measured. An amplifier and the sensitive electrode are combined in an assembly on the vibratory element thereby providing a low impedance amplifier output which in turn allows a narrow spacing around the vibratory element to prevent entry of contaminants. The vibratory element can be provided with a structure which allows measurements with various spatial resolution characteristics.

Sensor for non-contacting electrostatic detector

An electrostatic force microscope wherein electrostatic force applied to the detector is determined through obtaining the field distribution on several different shaped detectors with the calculation of the voltage distribution near the detector with the Finite Element Method to direct the measurement of the absolute charge amount on surface under test so that one can define the differences between the analysis and the results from the parallel plate model. Of interest is how large the error in the charge detection occurs in conjunction with thickness change of dielectric materials to be tested. There is provided a detector with cantilever which has proper shape for the spatial resolution of 10&mgr; made out of nickel foil for an electrostatic force microscope and the electrostatic force which appeared on it has been calculated.

Electrostatic force detector with cantilever for an electrostatic force microscope

An electrostatic force microscope for measuring electrostatic force of a sample under test including a detector comprising a cantilever arm having a tip formation at one end and located so that electrostatic force is induced at the tip due to electrostatic charge on the sample under test, an optical system for transforming bending of the cantilever arm due to electrostatic force induced at the tip into an electrical signal containing a frequency component of the electrostatic force induced at the detector tip, a source for applying bias voltage to the detector, a detector for detecting the frequency component of the electrostatic force induced at the detector tip so that a measurement of electrostatic force on the sample under test can be obtained, and an electrostatic shield operatively associated with the cantilever arm. The shield is located between the cantilever arm and the sample under test, in particular in close spaced relation to the arm. The cantilever arm and the shield are maintained at the same electrical potential so that lines of electrostatic force are terminated at the shield.

Electrostatic force detector with cantilever and shield for an electrostatic force microscope

In a computed tomography system using radiation, a large number of radiation beams are projected into a selected slice-like sectional portion of a subject to be reconstructed, in various directions. A profile of measured projection data is obtained from the radiation beams penetrated in parallel at each given angular interval. The profile of measured projection data thus obtained is subjected to a filtering operation to produce profiles of first modified projection data. The profile of modified projection data is recasted at properly selected intervals to produce second modified projection data. This results in a remarkable reduction of the amount of weight coefficients required in an interpolation to calculate the modified projection data for a large number of picture elements defined in matrix fashion on the sectional portion.

Computed tomography using radiation

An apparatus and method for tomographic analysis comprising a detecting system for detecting a number of radiation beams having penetrated a sectional area of a subject and producing projection data signals; a CPU and a memory for applying a filter function to the projection data signals by a convolution integration or by a computational technique included in a filtered-back projection, thereby calculating modified projection data signals, and conducting back projection operations only with respect to points in a partial region or subsection of the sectional portion area by means of the modified projection data, thereby calculating the radiation beam absorption coefficients at said points, the integral operation used in the calculation of the modified projection data signals being limited to an interval in which the quality of an image of said partial region or subsection to be displayed can exclusively be improved by the filter function; and a display unit for displaying the image of the partial region on the basis of said absorption coefficients.

Method and apparatus for subsection analysis using computed tomography

Growing community of inventors

Tokyo, Japan

Toshio Uehara