Abstract: Disclosed is a method of producing a microporous polymer membrane, comprising: providing a polymer material; melting the polymer material; forming a precursor film by cooling and crystallizing the molten polymer material using an air knife; extending the precursor film; annealing the extended precursor film, primary stretching the annealed precursor film; forming a preliminary membrane by subjecting the primary stretched film to secondary stretching at a high temperature, and forming a microporous polymer membrane by heat setting the preliminary membrane. A microporous polymer membrane produced by the method is also provided.

Abstract: Disclosed is a method of producing a microporous polymer membrane, comprising: providing a polymer material; melting the polymer material; forming a precursor film by cooling and crystallizing the molten polymer material using an air knife; extending the precursor film; annealing the extended precursor film, primary stretching the annealed precursor film; forming a preliminary membrane by subjecting the primary stretched film to secondary stretching at a high temperature, and forming a microporous polymer membrane by heat setting the preliminary membrane. A microporous polymer membrane produced by the method is also provided.

Abstract: There are provided PRAMS having a plurality of active regions located vertically in sequence and methods of forming the same. The PRAM and the method provide an approach to rapidly changing phase in a phase change layer pattern with a given design rule. A semiconductor substrate defining at least one reference active region is prepared in a cell array region and a peripheral circuit region. Other semiconductor substrates on a vertical line passing a main surface of the reference active region are located in sequence. The other semiconductor substrates define other active regions, respectively. A lower cell gate pattern is formed on the semiconductor substrate of the reference active region, and upper cell gate patterns are disposed on the other semiconductor substrates of the other active regions, respectively.

Abstract: There are provided PRAMS having a plurality of active regions located vertically in sequence and methods of forming the same. The PRAM and the method provide an approach to rapidly changing phase in a phase change layer pattern with a given design rule. A semiconductor substrate defining at least one reference active region is prepared in a cell array region and a peripheral circuit region. Other semiconductor substrates on a vertical line passing a main surface of the reference active region are located in sequence. The other semiconductor substrates define other active regions, respectively. A lower cell gate pattern is formed on the semiconductor substrate of the reference active region, and upper cell gate patterns are disposed on the other semiconductor substrates of the other active regions, respectively.

Abstract: There are provided PRAMS having a plurality of active regions located vertically in sequence and methods of forming the same. The PRAM and the method provide an approach to rapidly changing phase in a phase change layer pattern with a given design rule. A semiconductor substrate defining at least one reference active region is prepared in a cell array region and a peripheral circuit region. Other semiconductor substrates on a vertical line passing a main surface of the reference active region are located in sequence. The other semiconductor substrates define other active regions, respectively. A lower cell gate pattern is formed on the semiconductor substrate of the reference active region, and upper cell gate patterns are disposed on the other semiconductor substrates of the other active regions, respectively.

Abstract: There are provided PRAMS having a plurality of active regions located vertically in sequence and methods of forming the same. The PRAM and the method provide an approach to rapidly changing phase in a phase change layer pattern with a given design rule. A semiconductor substrate defining at least one reference active region is prepared in a cell array region and a peripheral circuit region. Other semiconductor substrates on a vertical line passing a main surface of the reference active region are located in sequence. The other semiconductor substrates define other active regions, respectively. A lower cell gate pattern is formed on the semiconductor substrate of the reference active region, and upper cell gate patterns are disposed on the other semiconductor substrates of the other active regions, respectively.