The aim of this study was to estimate genetic correlations between milk yield, somatic cell score (SCS), mastitis, and claw and leg disorders (CLDs) during first lactation in Holstein cows by using a threshold–linear random regression test-day model. We used daily records of milk, fat and protein yields; somatic cell count (SCC); and mastitis and CLD incidences from 46 771 first-lactation Holstein cows in Hokkaido, Japan, that calved between 2000 and 2009. A threshold animal model for binary records (mastitis and CLDs) and linear animal model for yield traits were applied in our multiple trait analysis. For both liabilities and yield traits, additive genetic effects were used as random regression on cubic Legendre polynomials of days on milk. The highest positive genetic correlations between yields and disease incidences (0.36 for milk and mastitis, 0.56 for fat and mastitis, 0.24 for protein and mastitis, 0.32 for milk and CLD, 0.44 for fat and CLD and 0.31 for protein and CLD) were estimated at about the time of peak milk yield (36 to 65 days in milk). Selection focused on early lactation yield may therefore increase the risk of mastitis and CLDs. The positive genetic correlations of SCS with mastitis or CLD incidence imply that selection to reduce SCS in the early stages of lactation would decrease the incidence of both mastitis and CLD.

We investigated the relationships between conception rates (CRs) at first service in Japanese Holstein heifers (i.e. animals that had not yet had their first calf) and cows and their test-day (TD) milk yields. Data included records of artificial insemination (AI) for heifers and cows that had calved for the first time between 2000 and 2008 and their TD milk yields at 6 through 305 days in milk (DIM) from first through third lactations. CR was defined as a binary trait for which first AI was a failure or success. A threshold-linear animal model was applied to estimate genetic correlations between CRs of heifers or cows and TD milk yield at various lactation stages. Two-trait genetic analyses were performed for every combination of CR and TD milk yield by using the Bayesian method with Gibbs sampling. The posterior means of the heritabilities of CR were 0.031 for heifers, 0.034 for first-lactation cows and 0.028 for second-lactation cows. Heritabilities for TD milk yield increased from 0.324 to 0.433 with increasing DIM but decreased slightly after 210 DIM during first lactation. These heritabilities from the second and third lactations were higher during late stages of lactation than during early stages. Posterior means of the genetic correlations between heifer CR and all TD yields were positive (range, 0.082 to 0.287), but those between CR of cows and milk yields during first or second lactation were negative (range, −0.121 to −0.250). Therefore, during every stage of lactation, selection in the direction of increasing milk yield may reduce CR in cows. The genetic relationships between CR and lactation curve shape were quite weak, because the genetic correlations between CR and TD milk yield were constant during the lactation period.

Mastitis is a common infectious disease of the mammary gland and a major problem in the dairy industry. We previously reported that forebrain embryonic zinc finger-like (FEZL) encoding a stretch of 12 glycines (p.Gly105[12]) instead of 13 glycines (p.Gly105[13]) is associated with a lower somatic cell score (SCS) in a family derived from Walkway Chief Mark. Here we report that the p.Gly105[12] allele is associated with a significantly decreased incidence of clinical mastitis in a large Holstein population. We genotyped the FEZL polymorphism in 918 randomly collected Holstein sires, and investigated the effect of the polymorphism on the estimated breeding value (EBV) for SCS and milk, fat, solids-not-fat, and protein yield, and on the number of cattle with clinical mastitis among daughters derived from these sires. The average EBV for SCS among sires carrying the heterozygous p.Gly105[12] was significantly lower than that among sires carrying the homozygous p.Gly105[13], whereas we found no unfavorable effects of this polymorphism on EBV for milk, fat, solids-not-fat, and protein yield. The proportion of cows with clinical mastitis derived from sires carrying heterozygous p.Gly105[12] was significantly lower than that of daughters derived from sires carrying the homozygous p.Gly105[13]. Thus, selection of sires carrying p.Gly105[12] could be beneficial in the dairy industry by reducing the incidence of mastitis.

We have investigated physical and electrical properties of Al2O3, HfO2, and their alloy films deposited on 300mm Si wafers by Atomic Layer Deposition (ALD). It is found that Al2O3 films are not crystallized even after the heat treatment of 1050°C, while HfO2 films are already crystallized even after a-Si deposition (530°C). The crystallization temperature can be higher by adding Al2O3 to HfO2. It is confirmed by in-plane XRD and plane views of TEM that HfAlOx films with lower Hf content (Hf/(Hf+Al) <30%) are amorphous without phase separation after annealing at 1050°C and 5sec. The dependences of equivalent oxide thicknesses (EOT) on the physical thicknesses of Al2O3, HfAlOx (Hf/(Hf+Al)∼22%), and HfO2 films in poly-silicon gate capacitors indicate that those dielectric constants k are ∼9, 14, and 23, respectively. The gate dielectric with EOT of 1.5nm and the leakage current density Jg of 3mA/cm2 can be fabricated with 2nm-thick HfAlOx (22%) film.

Vt Tuning in High-k nMOSFETs over Metal Gate WF Control M. Kadoshima, S. Sakashita, T. Kawahara, M. Inoue, M. Mizutani, Y. Nishida, A. Shimizu, Y. Takeshima. S. Yamanari, M. Anma, R. Mitsuhashi, Y. Satoh, S. Matsuyama, A. Tsudumitani, Y. Okuno, H. Umeda, J. Yugami, H. Yoshimura, and H. Miyatake Renesas Technology Corporation, 4-1, Mizuhara, Itami, Hyogo 664-0005, Japan Panasonic Corporation, 19 Nishikujo-kasugacho, Minami-ku, Kyoto 601-8414, Japan Phone: +81-72-787-2472, Fax: +81-72-789-3023, E-mail: kadoshima.masaru@renesas.com

We demonstrated the use of an in situ metal/high-k fabrication method for improving the performance of metal-insulator-semiconductor field-effect transistors (MISFETs). Gate-first pMISFETs with polycrystalline silicon (poly-Si)/TiN/HfSiON stacks were fabricated by techniques based on low-damage physical vapor deposition, in which high-quality HfSiON dielectrics were formed by the interface reaction between an ultrathin metal-Hf layer (0.5 nm thick) and a SiO2 underlayer, and TiN electrodes were continuously deposited on the gate dielectrics without exposure to air. Gate-first pMISFETs with high carrier mobility and a low threshold voltage (V-th) were realized by reducing the carbon impurity in the gate stacks and improving the V-th stability against thermal treatment. As a result, we obtained superior current drivability (I-on = 350 mu A/mu m at I-off = 200pA/mu m), which corresponds to a 13% improvement over that of conventional chemical vapor deposition-based metal/high-k devices.

In this paper, in order to obtain layout-independent transistors in recent fine-pitched LSI circuits, a completely stress-controlled shallow trench isolation (STI) process is proposed. In this process, a single-layered spin-on dielectric (SOD) film is used for STI gap filling without employing a complex hybrid structure. With this technique, the mechanical stress caused by STI is markedly suppressed. Subsequently, drain current (Id) modulation due to the STI stress is inhibited successfully. Thus, this technique is a very promising 45 nm node STI scheme with a high performance and a high reliability.

We have investigated a polycrystalline silicon (poly-Si)/chemical vapor deposited titanium nitride (CVD-TiN) stacked structure as a metal gate with a high-k for p-type metal insulator semiconductor field effect transistors (p-MISFETs). A divided-CVD method provided an appropriate effective work function (4.9-5.2eV) on HfSiON for p-MISFETs. However, the deposition of poly-Si on CVD-TiN films shifted the effective work function to a midgap (similar to 4.6 eV), and Ti, Hf, and Si diffused into poly-Si/CVD-TiN/high-k structures during poly-Si deposition. Then, we found that an increase in the deposition temperature of CVD-TiN films and the insertion of a physical vapor deposited (PVD)-TiN film between the poly-Si and CVD-TiN layers are effective in suppressing these diffusions. In particular, the insertion of the PVD-TiN film provided an appropriate effective work function of 4.9 eV. Therefore, we found that the diffusion control techniques for poly-Si/TiN/high-k stacked structures are highly effective for obtaining the appropriate work function for p-MISFETs.

We could obtain high performance gate-first pMISFET with TiN/HfSiON gate stacks fabricated with PVD-based in-situ method. High-quality Hf silicate gate dielectrics were formed by utilizing a solid phase interface reaction (SPIR) between a metal Hf layer and an SiO2 underlayer, and TiN electrodes were continuously grown on the gate dielectrics using a low-damage sputtering system without exposure to air.

The effects of the diffusion control technique by inserting physical vapor deposition (PVD)-TiN film between poly-Si and CVD-TiN films on the properties of p-MISFETs using poly-Si/TiN/HfSiON gate stacks have been studied. This insertion was effective in suppressing the diffusion of Si from poly-Si to HfSiON and was able to reduce the V th value by 0.12 V while keeping the equivalent oxide thickness and S value constant, when the thicknesses of the PVD and CVD-TiN films were 10 and 5 nm, respectively. Although too much ion implantation of fluorine into the substrate deteriorates S value and I ON , it was verified that this diffusion control technique, in conjunction with a moderate substrate fluorine implantation, provided a reduction of V th in pMIS without a deterioration of I ON .

1 Introduction Hf-based silicates and aluminates showing good thermal stability [1] and favorable energy-band alignment [2] have been intensively studied as most promising alternative gate dielectrics. Despite a number of efforts to improve the dielectric properties of such high-k thin films, reliability issues such as charge trapping and dielectric wear-out are still matters of research [3, 4], especially for metal-gate/high-k dielectric gate stack. In this work, we have focused on a HfAlO x (Hf/(Hf+Al)=~0.3)/SiON stack structure and studied its temperature dependence of leakage current from Al-gate, charge trapping properties and time-dependent dielectric breakdown (TDDB).

The effects of the nitrogen profile in the SiON-interfacial layer (IL) on the mobility in FETs employing a HfAIO/SiON gate dielectric have been investigated. In order to suppress the interdiffusion between HfAlO and SiON, the nitrogen concentration in SiON should be higher than 15 at%, while the substrate interface should be oxygen-rich in order to suppress the mobility reduction. By using an NO reoxidation of NH3 formed 0.4-nm-thick silicon nitride, the mobility reduction due to the SiON-IL was successfully suppressed, and electron and hole mobility of 92 % and 88 % of those for SiO2 at V-g = 1.1 V were obtained for HfAIO/SiON with equivalent oxide thickness (EOT) of 1.1 nm. By using nitrogen profile engineered SiON-IL, good equvalent oxide thickness (EOT) uniformity, low EOT, low gate leakage current, low defect density and symmetrical threshold voltage were all achieved, indicating that a poly-Si/HfAlO/SiON gate stack would be a candidate as an alternative gate structure for low standby power FETs of half-pitch (hp)65 and hp45 technology nodes.