Papers by Author: Hideki Shimizu

Abstract: To demonstrate the formation of 3C-SiC film on Si (111) at low substrate temperature, the effects of C₃H₈ on the crystalline quality of the 3C-SiC films on Si (111) have been investigated by changing the flow rate of C₃H₈ at the substrate temperature of 950 °C. The crystalline quality has been investigated by transmission electron microscope and X-ray diffraction. 3C-SiC is epitaxially grown on Si(111) and the 3C-SiC films are in either near single crystalline or highly oriented form with stacking faults and twin. It is expected that the film with good crystalline quality may grow at around 2.5 in the ratio of the flow rate of C₃H₈ to SiH₄ and any microstructures of 3C-SiC films on Si (111) can be controlled by accurately controlling the ratio of C/Si.

Abstract: In order to demonstrate the formation of 3C-SiC film on Si (111) at low substrate temperature, the effects of C3H8 on the crystallinity of the films on Si (111) have been investigated by changing the flow rate of C3H8 at the substrate temperature of 850 °C. Oriented polycrystalline 3C-SiC film grew under the C/Si of 3 – 5 with a-C. It is suggested that etching effects of growing surface by hydrogen radicals generated from C3H8 decomposition is lowered by lowering the substrate temperature. The crystallinity has been investigated by reflection electron diffraction (RED) and a X-ray diffraction (XRD). The thickness and the surface roughness of the films were investigated by an ellipsometric measurement.

Abstract: In order to demonstrate the formation of 3C-SiC film on Si (111) at low substrate temperature, the effects of C3H8 on the crystallinity of the films on Si (111) have been investigated by changing the flow rate of C3H8 at the substrate temperature of 950 °C. Nearly single-crystalline 3C-SiC film grew under the ratio of the flow rate of C3H8 to the flow rate of SiH4 (C/Si) of 2 - 2.5. From these results, it is suggested that C/Si shifts into higher with decreasing the substrate temperature. The crystallinity has been investigated by a reflection electron diffraction (RED) and a X-ray diffraction (XRD). The thickness and the surface roughness of the films were investigated by an ellipsometric measurement.

Abstract: The effects of C3H8 on the microstructures of the films on Si (111) have been investigated by changing the concentration of C3H8 from 0.5% to 5%. 3C-SiC film on Si (111) grown at the C3H8 concentration of 1% with relatively high flow rate of SiH4 (30 sccm) is single crystal and free from the contamination of W2C. By comparing the deposition rates of the films on Si (111) and Si (100) at different concentrations of C3H8, SiC growth on Si (111) is much more dependent on C3H8 concentration than that on Si (100). From these results it is suggested that SiC growth on Si (111) is strongly influenced by hydrogen radicals generated from C3H8 decomposition by the plasma and forms single crystal easier than on Si(100). It is expected that 3C-SiC epitaxial growth on Si (111) has higher deposition rate and lower substrate temperature than on Si (100). The crystallinity has been investigated by a reflection electron diffraction (RED) and a X-ray diffraction (XRD). The thickness and the surface roughness of the films were investigated by an ellipsometric measurement.

Abstract: 3C-SiC films grown on carbonized Si (100) by plasma-assisted CVD have been investigated with systematic changes in flow rate of monosilane (SiH4) and propane (C3H8) as source gases. The deposition rate of the films increased monotonously and the microstructures of the films changed from 3C-SiC single crystal to 3C-SiC polycrystal with increasing flow rate of SiH4. Increasing C3H8 keeps single crystalline structure but results in contamination of α-W2C, which is a serious problem for the epitaxial growth. To obtain high quality 3C-SiC films, the effects of C3H8 on the microstructures of the films have been investigated by reducing the concentration of C3H8. Good quality 3C-SiC single crystal on Si (100) is grown at low net flow rate of C3H8 and SiH4, while 3C-SiC single crystal on Si (111) is grown at low net flow rate of C3H8 and high net flow rate of SiH4. It is expected that 3C-SiC epitaxial growth on Si (111) will take placed at a higher deposition rate and lower substrate temperature than that on Si (100).

Abstract: This paper describes a measurement method for three-dimensional (3D) slit width deviations of long precision slot dies, which are essential for process control in manufacturing. A sensor unit consisting of two laser probes with their measurement axes aligned along the same Z-directional line but with opposite measurement directions, is placed between the two parts of the slot die to scan the two opposing surfaces of the parts along the X- and Y-axes. The variation of the sum of the laser probe outputs, which shows the deviation of the distance between the two surfaces, corresponds to the deviation of the slit width in the Z-direction. The 3D slit width deviations can be obtained accurately through scanning the entire surface in the X Y plane. In addition, the surface flatness of the parts can also be measured accurately by adding one more probe. Measurement experiments have been conducted on a precision grinding machine. The measurement results have indicated that the 3D slit width deviations and flatness can be measured with a repeatability error of less than 1 micron, which meets the requirement for quality control of slot dies.

Abstract: For effective medical treatment, sensors that can find foreign bodies such as tumors in early stage are required. This paper describes a new sensor for foreign body detection utilizing the fact that the property hardness of foreign bodies differs from that of normal tissues. It consists of a balloon probe, which is constructed with a thin rubber membrane inflated with compressed air, and an optical deformation analyzing system. Experiments are carried out using samples in which single hard balls are embedded to model single tumor in soft tissue. It was confirmed that this sensor can detect the existence of the hard ball and can also distinguish the inequality of size and hardness of the ball. Furthermore, experimental results detecting multi-objects showed that this sensor has the ability to detect the existence of multi objects and their relative positions simultaneously. By measuring the consistence of the arm and the abdomen of human body, it is proved that the sensor is also suitable for consistence measurement of human anatomy.

Abstract: Effects of the flow rate of C3H8 passed through hydrogen plasma on deposition rates and^microstructures of 3C-SiC films on Si (100) substrate were investigated by a reflection electron diffraction, an X-ray diffraction and an ellipsometric measurement. The deposition rate of the films increased independently of the flow rate of C3H8 with increasing the flow rate of SiH4. The films grown with increasing the flow rate of C3H8 kept single crystalline structure even at high flow rate of SiH4. Hydrogen radicals generated from C3H8 decomposition by plasma increase with increasing the flow rate of C3H8, and play important rolls to keep epitaxial growth.