Robust porous SiOCH/Cu interconnects with ultrathin sidewall protection liners

Robust porous low-k/Cu interconnects have been developed for 65-nm-node ultralarge-scale integrations (ULSIs) with 180-nm/200-nm pitched lines and 100-nm diameter vias in a single damascene architecture. A porous plasma-enhanced chemical vapor deposition (PECVD)-SiOCH film (k=2.6) with subnanometer pores is introduced into the intermetal dielectrics on the interlayer dielectrics of a rigid PECVD-SiOCH film (k=2.9). This porous-on-rigid hybrid SiOCH structure achieves a 35% reduction in interline capacitance per grid in the 65-nm-node interconnect compared to that in a 90-nm-node interconnect with a fully rigid SiOCH. A via resistance of 9.7 /spl Omega/ was obtained in 100-nm diameter vias. Interconnect reliability, such as electromigration, and stress-induced voiding were retained with interface modification technologies. One of the key breakthroughs was a special liner technique to maintain dielectric reliability between the narrow-pitched lines. The porous surface on the trench-etched sidewall was covered with an ultrathin plasma-polymerized benzocyclobuten liner (k=2.7), thus enhancing interline time-dependent dielectric breakdown reliability. The introduction of a porous material and the control of the sidewall are essential for 65-nm-node and beyond scaled-down ULSIs to ensure high levels of reliability.     

A GaAs MESFET with a partially depleted p layer for SRAMapplications

A GaAs MESFET with a partially depleted p layer that has a specific application to SRAMs has been developed. The short-channel effect is well suppressed for gate lengths down to 0.5 μm by a rather dense p layer buried under the channel. Its acceptor ion dose is as high as 2×10¹² cm^-2, which corresponds to a partially depleted condition. As for applications for SRAMs, it is possible to attain fully functional 7-ns 4-kb SRAMs that are operative at 75°C by using the FET with a 1-μm gate. A chip yield of 22% has been achieved in a 3-in wafer     

Aromatase activity and the effect of estradiol and testosterone on DNA synthesis in endometrial carcinoma cell lines

Human endometrial and breast carcinoma cell lines were examined for aromatase activity and the effects of sex steroids (estradiol and testosterone) on DNA synthesis. Aromatase activity was high (greater than 500 fmol/10(7) cells/24 h) in the cell lines MCF-7 and OMC-2, moderate (100-499 fmol/10(7) cells/24 h) in the cell lines HEC-59 and Ishikawa, and low (less than 100 fmol/10(7) cells/24 h) in the HHUA cell line. A substantial stimulation of DNA synthesis by estradiol (10(-9)M) was observed in cell lines HEC-59, OMC-2, and MCF-7, with an increase in [3H]thymidine uptake of over 250%. The Ishikawa cell line was stimulated moderately (115-249%). No estradiol-induced increase in DNA synthesis was observed in HHUA. Responsiveness of DNA synthesis to testosterone was observed in cell lines that showed the greatest response to estradiol, namely HEC-59, OMC-2, and MCF-7. Otherwise, estrogen-responsiveness did not always correlated with a significant aromatase activity. These data suggest that some but not all endometrial carcinomas may possess an aromatase-dependent growth stimulating system.     

Soybean protein suppresses hepatic lipogenic enzyme gene expression in Wistar fatty rats

The effects of dietary soybean protein on lipogenic enzyme gene expression in livers of genetically fatty rats (Wistar fatty) have been investigated. When Wistar fatty rats and their lean littermates (7-8-wk old) were fed a casein or soybean protein isolate diet containing hydrogenated fat (4% hydrogenated fat plus 1% corn oil) or corn oil (5%) for 3 wk, the hepatic messenger RNA concentrations and activities of lipogenic enzymes were significantly lower in rats fed soybean protein than in those fed casein, regardless of genotype or dietary fat. The conversion rates of thyroxine to triiodothyronine by liver microsomes and plasma triiodothyronine concentrations were lower in the fatty rats than in the lean rats and were significantly greater in rats fed soybean protein than in those fed casein. Conversely, plasma and liver triacylglycerol concentrations were lower in soybean protein-fed fatty and lean rats than in those fed casein. The body weight was less in the fatty rats fed soybean protein than in those fed casein after 3 wk of feeding. Moreover, dietary polyunsaturated fatty acids suppressed lipogenic enzyme gene expression in the lean rats but did not in the fatty rats. Dietary soybean protein appeared to be useful for the reduction of obesity.     

Non-African Burkitt's lymphoma in a young woman

Non-African Burkitt's lymphoma is presented in a 29-year-old, unmarried woman, who developed tumors in both breats and ovaries, ascites and pleural effusion. Assessment of B cells in the tumor cells, derived from ascites, pleural effusion and tumor tissue is 90%, surface IgM being consisted of 86%, in an average. Histologically, the tumor tissue demonstrates prominent, socalled starry-sky effect, and cytologically, tumor cells are poorly-differentiated lymphocytoid cells in their feautures.