摘要:
An apparatus and a method for performing a chemical vapor deposition process that reduces particle contamination of a wafer, wherein a cleaning gas including a fluorine radical is introduced into the process chamber to clean the chamber. After loading a wafer in the process chamber, a deposition gas is introduced into the chamber to form a film on the wafer. An inert gas as a back flow-preventing gas is introduced into the process chamber through a cleaning gas supply line to prevent the deposition gas from flowing back toward the cleaning gas supply line. Thus, the cleaning gas supply line is prevented from being contaminated by the deposition gas and particle formation on the wafer during deposition of the film is reduced, so that yield and reliability of the semiconductor device may be improved.
摘要:
A method of selecting a vocoder in a CDMA mobile communication system, includes the steps of: indexing shelves, slots, and vocoders, before sequentially selecting a shelf and a slot according to the order of index, and, after detecting a frame offset of a present call, calculating a number of frame offsets identical with the frame offset of the present call contained in the selected slot; and comparing the number of the frame offsets, which are identical with the present call's frame offset and contained in the slot sequentially selected, with numbers of the identical frame offsets contained in other slots, and selecting a slot having the fewest frame offsets identical with the present call's frame offset.
摘要:
The present invention relates to hepatitis B virus (hereinafter it refers to HBV) polymerase containing a histidine tag, RNase H enzyme derived from HBV polymerase and processes for preparation thereof. More particularly, the present invention relates to recombinant HBV polymerase, its RNase H domain with enzyme activity, expression vectors producing the enzymes in E. coli and processes for preparing the HBV polymerase and the RNase H enzyme which can be easily purified due to their histidine tags. And the present invention relates to uses of the HBV polymerase and the RNase H enzyme for screening antiviral agents.