Abstract: Methods of forming integrated circuit memory devices may include steps to form memory cell access transistors therein. These steps may include steps to form a gate line on a semiconductor substrate and then implant dopants of first conductivity type into the semiconductor substrate to define a self-aligned impurity region therein. A spacer layer of a first material is then formed on a sidewall and upper surface of the gate line. An interlayer insulating layer of a second material is then formed on the spacer layer. A series of selective etching steps are then performed using different etchants. For example, a step is performed to selectively etch the interlayer insulating layer to define a contact hole therein, using the spacer layer as an etching mask to protect the gate line from etching damage. A selective etching step is then performed to convert the spacer layer into a sidewall spacer on the sidewall of the gate line.

Abstract: A new casein is disclosed isolated from the milk of Korean cattle with a &bgr;-casein A1H genotype. Amino acid sequence analysis of the casein revealed a length of 209 amino acids, where, in comparison to the more conventional &bgr;-casein variant A2, at amino acid position 25, Arg is replaced by Cys, at position 88, Leu is replaced by Ile, at position 117, Gln is replaced by Glu, at position 175, Glu is replaced by Gln, and at position 195, Gln is replaced by Glu. The new casein variant disclosed can be mass produced by the selective breeding of individual bovines to produce large quantities of milk containing the new casein variant. In one example of such breeding, a female calf was born that subsequently produced the inventive casein at a yield of 4.5 kg per day. The new casein gene can be detected DNA hybridization analysis in bovines secreting the new casein.

Abstract: A contact hole for an integrated circuit substrate is fabricated by forming first and second layers on an integrated circuit substrate and a photoresist pattern on the second layer including a first opening therein. The second layer is etched through the first opening to define a sidewall therein while concurrently forming a polymer on the sidewall, so as to form a second opening in the second layer that is smaller than the first opening. The etching step preferably comprises the step of etching the second layer using a fluorocarbon to define a sidewall therein while concurrently forming a fluorocarbon polymer on the sidewall. The first layer is then etched through the second opening to form the contact hole to the integrated circuit substrate. A conductive layer may be formed in the contact hole to form a conductive contact that electrically contacts the integrated circuit substrate.

Abstract: The present invention relates to a purified casein phosphopeptide(CPP) having a novel amino acid sequence and a purified casein including same wherein the 25th Arg from N-terminal in a conventional CPP is replaced by Cys, rendering the CPPs to forming a dimer by disulfide bond. In the corresponding DNA sequence, cytosine is replaced by thymine to cause the amino acid replacement from Arginine(Arg) to Cysteine(Cys). The CPP or the casein containing same has an improved ability of solubilizing minerals and absorbing thereof in animals. The CPP or the beta-casein H containing same can be added to foodstuffs, beverages, medication, cosmetics, feed in an effective amount of enhancing a mineral absorption in animals. An oral composition comprising the beta-casein H or the inventive CPP and a pharmaceutically acceptable carrier can reduce or relieve a dentinal hypersensitivity.