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Rare earth element, Ce, doped Ge (Ge:Ce) three-dimensional crystal is fabricated on Si (001) via a solid source low-temperature molecular beam epitaxy. Ce affects the formation of the self-assembled Ge dot, including its structure, initial growth and the density because of the self-limited process to suppress the total energy contained in the surface, the interface and bulk stress. Owing to the compressive strain from Si substrate, the out-of-plane lattice parameters of Ge:Ce dots are larger than that of bulk Ge, while in-plane lattice constants are smaller. Based on the lattice constant change and the full width at half maximum of the Raman peaks found as a function of Ce concentration, the solid solubility limit of Ce in the substitutional sites of Ge is as high as 0.7 at%. The magnitude of Raman shift does not depend upon Ce concentration, which suggests the growth or incorporation of Ge:Ce dots on Si (001) is limited by the stress.

Mono-layered gold nanoparticles just below the surface of silicon oxide film have been formed by a gold negative-ion implantation at a very low-energy, where the deviation of implanted atoms was sufficiently narrow comparing to the size of nanoparticles. Gold negative ions were implanted into SiO 2 thin films on Si substrate at energies of 35, 15 and 1 keV. The samples were annealed in Ar flow for 1 h at 900 or 1000 °C. Cross-sectional TEM observation for the implantation at 1 keV showed existence of Au nanoparticles aligned in the same depth of 5 nm from the surface. The nanoparticles had almost same diameter of 7 nm. The nanoparticles were found to be gold single crystal from a high-resolution TEM image.

Two formation methods of delta-layered metal nanoparticles in thermally grown thin SiO 2 layer on Si substrate were investigated: (1) gold negative-ion implantation at low-energy for nanoparticle formation at a shallow depth of the oxide layer and (2) thermal diffusion after silver negative-ion implantation for formation at a deep depth. Gold negative ions were implanted at 1, 15 and 35 keV to SiO 2 /Si. At the low-energy implantation at 1 keV, the almost delta-layer of Au nanoparticles (about 8 nm in diameter) was obtained at a shallow depth of 5 nm after annealing at 900 °C. For formation at deep depth, silver negative-ions were implanted at 10 keV and 1 × 10 15 ions/cm 2 to 25-nm-thick SiO 2 /Si. After annealing at 700 °C, all formed nanoparticles with 6 nm in diameter aligned at the same deep depth, i.e. almost delta-layered Ag nanoparticles, at the minimum distance of 2 nm from the boundary to Si. It is found from high resolution TEM observation that both almost delta-layered nanoparticles of Au and Ag were single crystals.

Metal nanoparticles in application for silicon based single electron devices are formed in a thin SiO 2 layer such as gate oxide layer on silicon substrate. The TEM observation is reliable but takes much effort and a long time for obtaining information about state of nanoparticles, i.e. particle size, distribution depth. Here, optical reflection property from multiple layer structure on Si was studied by experiments and with theoretical analysis. We proposed a calculation method of the reflectance from Au implanted 50-nm-thick SiO 2 film on Si substrate with three-layers model of the top SiO 2 , a composite layer with Au nanoparticles, and bottom SiO 2 layer. The experimentally obtained reflectance spectra from a sample at 35 keV–1×10 16 ions/cm 2 are well fitted by the proposed analysis of changing particle size and distribution depth based on the depth profiles of implanted atoms.

This study deals with nondestructive evaluation of the solder ball joints in BGA package. In order to establish the fast, two-dimensional, non-contact and non-destructive method for the evaluation of solder joints, a new technique based on the infrared thermograph was developed, in which the surface temperature of solder ball joints was measured in the thermal cycle with abrupt cooling after heating. Two parameters were used to evaluate the bonding state of the solder ball joints. One parameter is the temperature change of solder ball in the thermal cycle with the thermal shock due to abrupt cooling, which shows large decrease in poor bonding and slight decrease in good bonding. Another one is the temperature ratio between the solder ball and surrounding molded area, or dimensionless temperature. This value decreases with applying the thermal shock to poor bonding joints, while good solder ball joints keeps constant values regardless of thermal shock. These differences in two parameters are caused from the different thermal conductivity at the bonding interface of solder ball, which were confirmed by the FEM analyses of solder ball joints. It was also confirmed that the second parameter was a preferable parameter for the evaluation of solder ball joints, since the initial heating temperature as well as cooling time did not influence it.

Two formation methods of nanoparticles distributed at a certain depth in a delta layer by negative ion implantation were investigated. Such delta layer formation of isolated metal nanoparticles is desired in a very thin gate oxide film, with thickness of less than 10 nm for the development of a single electron device using nanoparticles as very small capacitance for Coulomb blockade. We have tried two methods by metal negative ion implantation in a thermally grown SiO2 film on Si substrate and postannealing for (1) a delta layer formation of gold nanoparticles in the surface region of SiO2 film, and for (2) a delta layer formation of silver nanoparticles in the bottom region of SiO2 film. In the former with gold negative ion implantation with a low energy, the depth distribution of nanoparticles formed at annealing at less than 900 °C depended on depth deviation of implanted atoms. The almost delta layer of Au nanoparticles with diameters of 4–8 nm was obtained just under the surface by Au negative ion implantation at 1 keV and annealing at 900 °C. In the latter with silver negative ion implantation at 10 keV, 1×1015 ions/cm2, 25-nm-thick SiO2/Si, and annealing at 700 °C, Ag nanoparticles with a diameter of 6–8 nm were aligned at the same depth in a delta layer in the bottom region of the SiO2 at a distance of 2 nm from the boundary.

Formation of silver nanoparticles formed by silver negative-ion implantation in a thin SiO 2 layer and its I – V characteristics were investigated for development single electron devices. In order to obtain effective Coulomb blockade phenomenon at room temperature, the isolated metal nanoparticles should be in very small size and be formed in a thin insulator layer such as gate oxide on the silicon substrate. Therefore, conditions of a fine particles size, high particle density and narrow distribution should be controlled at their formation without any electrical breakdown of the thin insulator layer. We have used a negative-ion implantation technique with an advantage of “charge-up free” for insulators, with which no breakdown of thin oxide layer on Si was obtained. In the I – V characteristics with Au electrode, the current steps were observed with a voltage interval of about 0.12 V. From the step voltage the corresponded capacitance was calculated to be 0.7 aF. In one nanoparticle system, this value of capacitance could be given by a nanoparticle of about 3 nm in diameter. This consideration is consistent to the measured particle size in the cross-sectional TEM observation. Therefore, the observed I – V characteristics with steps are considered to be Coulomb staircase by the Ag nanoparticles.

In this study, a ultrasonic evaluation was performed on the bonded areas in the semiconductor devices. The capillary or bonding tool fixed with epoxy resin holder was used for the transmission of ultrasound from the probe to wire bonded area and for the reception of reflected wave from bonded area. The ball shear test and EPMA analysis were also carried out for the evaluation of strength and wire boded area. The comparison between the ultrasonic test and shear test showed that the amplitude change from the wire bonded area is related with the very short time range and is small. The wave analyses of reflected wave proposed a available parameter for the nondestructive evaluation of wire bonded area, which showed good relation with the shear strength. It was also shown that this parameter depends upon the length of epoxy resin holder and was deeply related to the transmission of the ultrasound from capillary to holder in the measurement.

For local control in patients with endocrine-refractory prostate cancer, an intra-arterial chemotherapy regimen comprising methotrexate (MTX), Adriamycin (ADM), and cisplatin (CDDP) was evaluated. A total of 19 patients having a mean age of 66.4 +/- 8.8 years and a mean performance status (PS) of 1.3 +/- 1.0 were enrolled. Of these patients, 3 had proved to be resistant to initial endocrine therapy and the remaining 16 had relapsed from disease stabilization after endocrine therapy. The catheter tip was placed in the internal iliac artery in 16 cases, in the common iliac artery in 2 cases, and in the aorta in 1 case after occlusion of the contralateral feeding artery. The intraarterial chemotherapy was performed mainly using MTX (30 mg/m2), ADM (30 mg/m2), and CDDP (50 mg/m2) as one course and was repeated for a mean of 2.9 +/- 2.3 courses. Then, in an outpatient clinic, 5-fluorouracil (5-FU), ADM, or MTX was given intra-arterially as maintenance chemotherapy until re-relapse. As based on the criteria for evaluation of nonsurgical therapy in prostate cancer proposed by the Japanese Urological Association, the prostatic lesion showed a partial response (PR) in 9 cases and no change (NC) in 10 cases. As judged from the response of prostate-specific antigen (PSA), a complete response (CR) was obtained in 6 cases, a PR, in 3 cases; and NC and progressive disease (PD), in 2 cases each. Therefore, the overall response rate was 63%. Improvement in the symptoms was observed in 83% of patients. The duration of the response was 15.1 +/- 10.5 months for the PR cases and 7.4 +/- 5.7 months for the NC cases. Furthermore, the mean survival time observed in the PR group was 38.9 months, which was better than that seen in the NC (16.4 months) and PD (10.5 months) groups. These results suggest that intra-arterial chemotherapy may become an option for the treatment of locally advanced and endocrine-refractory prostate cancers. Using a reservoir, this chemotherapy can be easily given in an outpatient clinic.

Sixteen years follow-up was performed in a male of long-standing alcohol indulgence who had an alcoholic liver disease at the outset, followed by alcoholic pancreatitis which progressed finally to pancreatic calcification. During this course, the abnormalities of endoscopic pancreatogram were unremittingly progressive, whereas exocrine and endocrine pancreatic dysfunction remained fluctuating, but ultimately deteriorated. In contrast functional and histological abnormalities of the liver were not progressive but returned toward normal. The follow-up observations in this case suggest that some cases of typical alcoholic pancreatitis may have unremittingly progressive morphologic changes with fairly well reserved capacity of exocrine and endocrine pancreatic functions and their hepatic lesions may not be in parallel with pancreatic lesions.

The pancreatic duct system was studied with repeated endoscopic retrograde pancreatography in 31 patients with chronic pancreatitis, 32 patients with suspected chronic pancreatitis, and 16 controls without pancreatic disease. In chronic alcoholic pancreatitis the pancreatograms showed marked changes during the initial examination with progression even after abstinence or reduction of drinking. In the alcoholics with suspected chronic pancreatitis, progressive lesions in branch ducts with almost intact main ducts were recognized. In contrast, no remarkable alterations on serial pancreatograms were observed in nonalcoholic cases with definite or suspected chronic pancreatitis. These results suggest that pancreatic duct lesions play an important role in the development and progression of chronic alcoholic pancreatitis in contrast to chronic nonalcoholic pancreatitis.

In order to elucidate the functional states of the pancreas in the asymptomatic latent stage of chronic alcoholic pancreatitis, 45 chronic alcoholics with no obvious pancreatic structural abnormalities judged by endoscopic pancreatography were studied by pancreozymin-secretin test. We found three patterns of exocrine pancreatic function in alcoholics with or without cirrhosis: normal secretion (40%), hyposecretion (29%) and hypersecretion (31%). In the hyposecretory group, the amylase output proved to be impaired more frequently. In the hypersecretory group increases were observed in one or more of the following parameters, volume, bicarbonate output and amylase output. However, increase in volume was a fundamental condition in this hypersecretion. This study confirmed that exocrine pancreatic hyposecretion and hypersecretion were almost equally frequent in asymptomatic chronic alcoholics with no obvious pancreatographic abnormalities. These results suggest that ongoing exocrine pancreatic dysfunctions exist in the subclinical stage of chronic alcoholic pancreatitis.