‘Giant’ magnetoresistance in obliquely co-evaporated Co-Ag films

Magnetoresistance (MR) measurements at room temperature have been performed on obliquely (co-) evaporated Ag-Co films deposited at room- and elevated-temperatures. The ‘giant’ magnetoresistance ratio (max. 13% for a composition of about Co35Ag65) over a wide range of compositions has been measured. The films are polycrystalline and grown in a columnar morphology. The columnar diameter depends on the thickness and is < 20 nm at 400 nm thickness. From XRD, NMR and saturation magnetization (Ms) vs. at% Ag, one can conclude that the films consist of Co-Co and Ag-Ag clusters. The coercivity depends on the thickness of the films (100–700 nm) and varies from 5 to 15 kA/m

NMR measurements on obliquely evaporated Co-Cr films

The distribution of the hyperfine fields or the resonance frequencies in metals and alloys obtained by NMR measurements have been known for a long time. Recently, new experimental data have been published about thin films for studying their chemical inhomogeneities. An example is the study on sputtered and evaporated Co-Cr layers. In this paper we report on the compositional distribution of co-evaporated Co-Cr films by using the Co spin-echo NMR technique. For comparison single source evaporated samples of Co-Cr and pure Co as well as two alloyed ribbons (¿bulk¿ samples) have also been measured. Based on the NMR results the local Cr concentration of the ferromagnetic and less ferromagnetic regions are determined. In comparison the data from the co-evaporated films, even at low substrate temperature, have clearly shown the presence of a process-induced compositional separation. This is in qualitative agreement with the magnetic properties of the samples

W-CMP for sub-micron inverse metallisation

Chemical Mechanical Polishing (CMP) of tungsten for an inverse metallisation scheme is investigated. The influence of CMP parameters on removal rate and uniformity is studied. The main effects on the removal rate are the applied pressure and the rotation rate of the polishing pad. To the first order Preston's equation is obeyed. The uniformity is best with equal rpm of pad and wafer and with perforated pads. Also, pattern density effects of CMP of W/PETEOS are investigated. Dishing increased at larger W-linewidth. Oxide erosion increased at larger pattern density and smaller W-linewidth. Electrical measurements on submicron (0.4 and 0.5 ¿m) test structures yielded good CMP results

Modelling of dishing for metal chemical mechanical polishing

In this paper, a physical model for the development of dishing during metal chemical mechanical polishing (CMP) is proposed. The main assumption of the model is that material removal occurs predominantly at the pad/wafer contacts. The distribution of pad/wafer contact size is studied first. This distribution is used as an input for a model of the dependence for the material removal rate on the line width. A relation that describes the development of dishing as a function of overpolish time will be presented. The model describes to a great accuracy the observed dishing effects, using one free paramete

Microstructure of co-evaporated CoCr films with perpendicular anisotropy

Coevaporation of Co and Cr is applied to achieve good magnetic characteristics of media deposited at low temperature. The opposed oblique incidence vapor flux induces a columnar alignment parallel to the evaporation plane. Further, a process-induced segregation is present which introduces separated Co-rich and Cr-rich regions. A selective etching process is carried out to find proof of this. With increasing process temperature, nonelongated columns develop. The columnar axes are inclined towards the Co source at a smaller angle than the angle of incidence. The texture axes are also inclined, as are the anisotropy axes. The process-induced segregation results in an enhanced coercivity and saturation magnetization. A small in-plane anisotropy coincides with the direction of columnar alignment. At a higher process temperature, the column, texture, and anisotropy axis tilting decrease

The significance of insecure attachment and disorganization in the development of children's externalizing behavior: A meta-analytic study

This study addresses the extent to which insecure and disorganized attachments increase risk for externalizing problems using meta-analysis. From 69 samples (N = 5,947), the association between insecurity and externalizing problems was significant, d = 0.31 (95% CI: 0.23, 0.40). Larger effects were found for boys (d = 0.35), clinical samples (d = 0.49), and from observation-based outcome assessments (d = 0.58). Larger effects were found for attachment assessments other than the Strange Situation. Overall, disorganized children appeared at elevated risk (d = 0.34, 95% CI: 0.18, 0.50), with weaker effects for avoidance (d = 0.12, 95% CI: 0.03, 0.21) and resistance (d = 0.11, 95% CI: −0.04, 0.26). The results are discussed in terms of the potential significance of attachment for mental health

Chronic constipation in the elderly: an unusual presentation of colonic dysmotility in an elderly patient.

Introduction. Chronic constipation is common in the elderly, and often no underlying pathology is found. Primary colonic dysmotility has been described in children but is rare in the elderly. Case report. We present an 82-year-old female with long standing constipation presenting acutely with large bowel obstruction. Laparotomy and Hartman's procedure was performed, and a grossly distended sigmoid colon was resected. Histology revealed a primary myopathic process. Conclusion. Primary colonic myopathy should be considered in elderly patients presenting with large bowel obstruction and a long preceding history of constipation, particularly when previous endoscopic examinations were normal

Optimization of nitridation conditions for high quality inter-polysilicon dielectric layers

Nitridation of deposited high temperature oxides (HTO) was studied to form high quality inter-polysilicon dielectric layers for embedded non volatile memories. Good quality dielectric layers were obtained earlier by using an optimized deposition of polysilicon and by performing a post-dielectric anneal in a rapid thermal processor. In the present paper the quality is further improved by means of optimization of the post-dielectric anneal. The influence of temperature, time and pressure during annealing on the electrical properties is investigated. Electrical characterization by means of charge-to-breakdown (Qbd) and I-V measurements on simple capacitor structures evaluates the electrical properties of the layers. It is shown that an (optimized) rapid thermal N2O anneal leads to a very high charge to breakdown (Qbd ¿ 25 C/cm2), low charge trapping and low leakage currents