초록 ▼

A floating gate memory device has a floating gate and an insulating layer on the floating gate. A control gate is on the insulating layer. The insulating layer is made up of a molecular matrix with ionic complexes distributed in the molecular matrix. By the application of an electric field, the ioni

A floating gate memory device has a floating gate and an insulating layer on the floating gate. A control gate is on the insulating layer. The insulating layer is made up of a molecular matrix with ionic complexes distributed in the molecular matrix. By the application of an electric field, the ionic complexes are dissociable in the molecular matrix to change the resistivity (or conductivity) of the insulating layer. By switching between a high resistivity (low conductivity) state, where charge is retained by the floating gate, to a low resistivity (high conductivity) state, the charge stored on the floating gate can readily drained off to the gate electrode.

대표청구항 ▼

A floating gate memory device has a floating gate and an insulating layer on the floating gate. A control gate is on the insulating layer. The insulating layer is made up of a molecular matrix with ionic complexes distributed in the molecular matrix. By the application of an electric field, the ioni

A floating gate memory device has a floating gate and an insulating layer on the floating gate. A control gate is on the insulating layer. The insulating layer is made up of a molecular matrix with ionic complexes distributed in the molecular matrix. By the application of an electric field, the ionic complexes are dissociable in the molecular matrix to change the resistivity (or conductivity) of the insulating layer. By switching between a high resistivity (low conductivity) state, where charge is retained by the floating gate, to a low resistivity (high conductivity) state, the charge stored on the floating gate can readily drained off to the gate electrode. 1. An ion implantation apparatus comprising a vacuum chamber, an ion beam generator to generate an ion beam in the vacuum chamber, an implant wheel in the vacuum chamber, having a plurality of circumferentially distributed wafer support elements each having a wafer support surface canted inwardly towards the centre of the implant wheel, a scanning arm mounted for reciprocal movement about a scan axis and having a free end supporting the implant wheel for rotation about a wheel axis, so that rotation of the implant wheel about the wheel axis brings the wafer support elements successively to intercept the ion beam and reciprocation of the scanning arm about the scan axis scans the ion beam across the wafer support elements, wherein the wheel is rotatable with respect to the arm about a tilt axis, which substantially intersects the wheel axis and ion beam, to vary the angle of implantation, and wherein the scan axis is substantially parallel to the direction of the ion beam, and the direction of the wheel axis is offset from the direction of the scan axis such that the ion beam is substantially perpendicular to the wafer support surfaces when the implant wheel is not tilted. 2. An ion implantation apparatus according to claim 1, wherein the tilt axis is orientated between a direction in which it is substantially perpendicular to the wheel axis, and a direction in which it passes substantially through the plane of the substrate support for the substrate being scanned by the ion beam. 3. An ion implantation apparatus according to claim 1, wherein the tilt axis is substantially perpendicular to the wheel axis. 4. An ion implantation apparatus according to claim 1, wherein the tilt axis passes substantially through the plane of the substrate support for the substrate being scanned by the ion beam. 5. An ion implantation apparatus comprising: a vacuum chamber, an ion beam generator to generate an ion beam in the vacuum chamber, an implant wheel provided in the vacuum chamber, having a plurality of circumferentially distributed wafer support elements, a scanning arm mounted for reciprocal movement about a scan axis and having a free end supporting the implant wheel for rotation about a wheel axis, so that rotation of the implant wheel about the wheel axis brings the wafer support elements successively to intercept the ion beam and reciprocation of the scanning arm about the scan axis scans the ion beam, across the wafer support elements, and a motor for driving the scanning arm, the motor having a drive shaft, a cycloid type gearbox connected to the drive shaft of said motor and having an output shaft driving the scanning arm, wherein a first rotary position detector is provided on the drive shaft and a second rotary position detector is provided on the output shaft. 6. A method of verifying the mechanical integrity of an apparatus according to claim 5, the method comprising the steps of: taking a reading from the second rotary position detector, calculating the theoretical position of the motor from the reading taken from the second rotary position detector and from the gearbox ratio, measuring the actual position of the motor from the first rotary position detector, and comparing the actual position of the motor with the theoretical position of the motor. 7. A method of correcting a velocity profile for an apparatus according to claim 5, the method comprising the steps of: driving the scan arm across a range of movement, and noting readings from both rotary position detectors in each position, calculating from each first rotary position detector reading and from the gearbox ratio the theoretical second rotary position detector reading in each position, subtracting the theoretical second rotary position detector reading from the actual second rotary position detector reading in each position, processing the data generated in order to remove errors generated by sources other than second rotary position detector