This invention relates to the formation of a spacer layer on the barrier layer of a dual layer barrier type semiconductor device.
In fabricating semiconductor devices, the so-called dual layer barrier structure is often employed in which an intermediate dielectric layer is deposited between two insulator layers, which layers are deposited on a semiconductor substrate. By way of example, in forming a dual layer barrier semiconductor device, such as a capacitor, a lower electrode is formed on the substrate and then an upper electrode is formed on the lower electrode in the intermediate dielectric layer. A semiconductor material is then grown on the upper electrode.
The upper electrode and the semiconductor material layer are both formed by the process of chemical vapor deposition (CVD). A disadvantage of this process, however, is that the upper electrode is often formed over the intermediate dielectric layer before the layer is completely cured. If the upper electrode is formed before the intermediate dielectric layer is completely cured, then the dielectric properties of the intermediate dielectric layer are degraded and the resulting capacitor is less effective.
One technique for preventing the intermediate dielectric layer from being degraded prior to being cured is to deposit a conformal or conformalized spacer layer of a suitable dielectric material, e.g., silicon nitride, on the upper surface of the intermediate dielectric layer prior to depositing the upper electrode thereon. This technique prevents the dielectric properties of the intermediate dielectric layer from being degraded prior to the deposition of the upper electrode. However, this technique does not completely prevent the intermediate dielectric layer from being degraded prior to the deposition of the upper electrode.
Therefore, what is needed is a technique for preventing the intermediate dielectric layer of a dual layer barrier semiconductor device from being degraded prior to the deposition of an upper electrode thereon.Mifepristone pharmacokinetics in pregnancy and in the neonate.
Mifepristone, a synthetic compound related to progesterone, is the only medication that can induce premature labor at any stage of gestation. One of its metabolites, 20 alpha-hydroxyprogesterone caproate, also can be used to induce cervical ripening. The objective of this study was to determine the pharmacokinetics of mifepristone and 20 alpha-hydroxyprogesterone caproate during pregnancy and in the neonate. Maternal serum concentrations of mifepristone and 20 alpha-hydroxyprogesterone caproate were measured before and at 24, 48, 72, 96, and 120 hours after a single oral administration of 200 mg of mifepristone to ten women in early pregnancy, ten women in the midtrimester of pregnancy, and ten women in the last trimester of pregnancy. The maternal and neonatal serum concentrations of mifepristone and 20 alpha-hydroxypro 0b46394aab