Asahi Glass Company, Limited

Tohoku University

Other

Masaaki Takata

Mitsumasa Koyanagi

Kei Iwata

Tomonori Ogawa

Takuya Nakagawa

Nobuo Kageyama

Jiro Nishihama

Ryusuke Morita

Long Shao

Susumu Otaguro

The present invention relates to an optical member for deep ultraviolet having a wavelength of 250 nm or shorter, containing a synthetic silica glass which does not substantially contain a halogen element, has a maximum OH group content of less than 10 ppm by weight, has contents of ODC (oxygen deficient centers) and E-prime center of each less than 1&#xd7;10cm, does not substantially contain SiH and peroxy linkage, and has a fictive temperature of 1,050&#xb0; C. or lower.

Optical member for deep ultraviolet and process for producing same

The present invention provides a synthetic silica glass for an optical member in which not only a fast axis direction in an optical axis direction is controlled, and a birefringence in an off-axis direction is reduced, but a magnitude of a birefringence in the optical axis direction is controlled to an arbitrary value, such that an average value of a value BR cos2&#x3b8;defined from a birefringence BR and a fast axis direction &#x3b8;as measured from a parallel direction to the principal optical axis direction is defined as an average birefringence AveBR cos2&#x3b8;, and when a maximum value of a birefringence measured from a vertical direction to the principal optical axis direction of the optical member is defined as a maximum birefringence BRin an off-axis direction, the following expression (1-1) and expression (2-1) are established:&#x2212;1.0&#x2266;AveBR cos2&#x3b8;&#x3c;0.0&#x2003;&#x2003;(1-1)0.0&#x2266;BR&#x2266;1.0&#x2003;&#x2003;(2-1).

Synthesized silica glass for optical component

A process for producing a nonvolatile semiconductor memory having a mixed or laminated structure of a hardly oxidizable material composed of a hardly oxidizable element having Gibbs' free energy for forming oxide higher than that of Si under the same temperature condition at 1 atm and in temperature range of 0&#xb0; C. to 1,200&#xb0; C. and an oxide of an easily oxidizable material composed of an element having Gibbs' free energy for forming oxide lower than that of Si under the same temperature condition at 1 atm in the temperature range and Si. The process includes forming a portion of the hardly oxidizable material and a portion of the oxide by physical forming method and carrying out heat treatment in oxidizing and reducing gas mixture. The ratio of the gases and the temperature are controlled so that the hardly oxidizable material is reduced and the oxide is oxidized in the temperature range.

Nonvolatile semiconductor memory element excellent in charge retention properties and process for producing the same

A nonvolatile semiconductor memory device which can shorten data writing and erasing time, significantly improve the endurance characteristic and be activated with low power consumption includes an insulating layer with electric insulation, wherein, a charge retention layer formed adjacent to a tunnel insulating film contains nano-particles comprised of a compound which is constituted from at least one single-element substance or chemical compound having a particle diameter of at most 5 nm functions as a floating gate, and which are independently dispersed with a density of from 10to 10particles per square centimeter.

Nonvolatile semiconductor memory device and manufacturing process of the same

A nonvolatile semiconductor memory device including a source region and a drain region formed on a surface of a semiconductor substrate, a channel-forming region formed so as to connect the source region and the drain region or so as to be sandwiched between the source region and the drain region, a tunnel insulating film formed in contact with the channel-forming region, a charge retention layer formed adjacently to the tunnel insulating film, a gate insulating film formed adjacently to the charge retention layer, and a control gate formed adjacently to the gate insulating film. The charge retention layer includes an insulating matrix having, per nonvolatile semiconductor memory device, one conductive nano-particle which is made of at least one single-element substance or chemical compound that functions as a floating gate.

Nonvolatile semiconductor memory device having nanoparticles for charge retention

A thermal treatment system for semiconductors comprises an outer tube made of silicon carbide, a base hermetically supporting a lower portion of the outer tube, a lid selectively opening and closing an opening formed in a central portion of the base, and a reactor wall surrounding an outer peripheral wall and the like of the outer tube and having a heater provided on an inner side, wherein an annular sealing member and an annular supporting member are interposed between the outer tube and the base, and wherein the supporting member has an effective heat transfer coefficient of 50 to 2,000 W/(m&#xb7;K).

Growing community of inventors

Tokyo, Japan

Masaaki Takata