摘要:
A semiconductor memory device comprising a source and a drain formed in a P-type semiconductor substrate and a floating gate and a control gate constituting a two-layer gate. Electric-field moderating layer is provided in the P-type semiconductor substrate to contact with a side face of the drain. P-type region is formed in contact with channel region side surface and bottom surface of the electric-field moderating layer. P-type region lower part of the P-type region in contact with the bottom surface of the electric-field moderating layer is given a lower impurity concentration than P-type region side part formed at the channel region side of the electric-field moderating layer. By this means it is possible to increase the writing speed of the semiconductor memory device while suppressing delay in the switching speed during reading operation.
摘要:
A stable erythropoietin preparation and a process for formulating the same are disclosed.Erythropoietin is useful in the treatment or diagnosis of anemia, but it is an instable substance. In order to provide a stable erythropoietin preparation, it is formulated with one or more stabilizers selected from the group consisting of polyethylene glycols, proteins, sugars, amino acids, inorganic salts, organic salts and sulfur-containing reducing agents.
摘要:
A semiconductor device having an enhancement-type MOS structure which can prevent large leakage current is disclosed. A high-concentration region for threshold-value regulation use formed in a channel region below a gate electrode in an enhancement-type transistor is caused to be contiguous with a source region and not contiguous with a drain region. Herein, the distance between the high-concentration region and the drain region is set so as to preclude the depletion layer extending from the drain region side from reaching the high-concentration region. Therefore, the electrical field in the depletion layer does not become the critical field which causes avalanche or Zener breakdown, and so leakage current can be caused to be reduced.
摘要:
In a nonvolatile semiconductor memory, a floating gate electrode is disposed above a silicon substrate between source and drain regions, through a tunnel film, and a control gate electrode is disposed above the floating gate electrode through an insulating film. The substrate is grounded and at least two negative voltages are respectively applied to the control gate electrode, so that a voltage is applied to the tunnel film. In these cases, charge retention properties are evaluated. The voltages applied to the control gate electrode are controlled so that the voltage applied to the tunnel film does not exceed a voltage applied to the tunnel film during a memory operation. A charge retention property when no voltage is applied across the control gate electrode and the substrate, i.e., when no voltage is externally applied to the tunnel film, is estimated by the charge retention properties when the two voltages are applied to the control gate electrode.
摘要:
An anti-tumor preparation containing cells of Streptococcus equisimilis and a process for preparing the preparation which comprises subjecting the cells to heat treatment in a salt solution with or without penicillin treatment.
摘要:
A semiconductor device having an enhancement-type MOS structure which can prevent large leakage current is disclosed. A high-concentration region for threshold-value regulation use formed in a channel region below a gate electrode in an enhancement-type transistor is caused to be contiguous with a source region and not contiguous with a drain region. Herein, the distance between the high-concentration region and the drain region is set so as to preclude the depletion layer extending from the drain region side from reaching the high-concentration region. Therefore, the electrical field in the depletion layer does not become the critical field which causes avalanche or Zener breakdown, and so leakage current can be caused to be reduced.
摘要:
A floating gate of a semiconductor memory device has a gate bird beak on an end portion thereof. Further, a positional relationship between the floating gate and a drain is controlled such that a depletion layer formed within the drain in a non-selected state of the semiconductor memory device faces the gate bird beak without interposing the drain therebetween. Accordingly, drain disturbance can be efficiently prevented.