公开(公告)号：EP0843896A1

公开(公告)日：1998-05-27

申请号：EP96916640.0

申请日：1996-05-24

申请人： NATIONAL SEMICONDUCTOR CORPORATION

发明人： BERGEMONT, Albert ,  MEAD, Carver, A. ,  CHI, Min-hwa

IPC分类号： H01L27 ,  H01L31

CPC分类号： H01L31/1105 ,  H01L27/14681

摘要： A technique for decreasing the effective gain of a bipolar phototransistor at high light levels makes the image usable over a greatly extended range of illumination conditions. The effective current gain at high light levels is reduced by fabricating a 'non-ideal' emitter, such as by inserting a thin 20Å tunnel oxide between the emitter and base junction. The tunnel oxide between the emitter and base serves as a variable resistor as well as a good junction for carrier injection from the emitter. The total base voltage is the sum of the oxide voltage and the intrinsic base voltage. At high image intensity, the bipolar phototransistor will gradually enter into the saturation mode, i.e., the base to collector junction is forward biased. The beta is thus reduced. The bias of the collector should be about 0.3 - 0.8V higher than the emitter at the 20Å tunnel oxide thickness for optimum operation.

公开(公告)号：EP0745257B1

公开(公告)日：2000-05-03

申请号：EP95943771.6

申请日：1995-12-08

申请人： NATIONAL SEMICONDUCTOR CORPORATION

发明人： BERGEMONT, Albert ,  CHI, Min-hwa

IPC分类号： G11C11/56

CPC分类号： G11C11/5628 ,  G11C11/5621 ,  G11C11/5635 ,  G11C2211/5625

摘要： Multiple logic levels can be programmed into a single EPROM or FLASH memory cell by applying one of a corresponding number of programming voltages to the control gate of a memory cell that has a punch-through current during programming. During programming, the punch-through current forms substrate hot electrons which, in addition to the channel hot electrons, accumulate on the floating gate. By utilizing the punch-through hot electrons, a much lower control gate voltage can be utilized during programming. More importantly, however, once the channel hot electrons cease to exist, the punch-through hot electrons and holes converge to a stable charge that is related to the control gate voltage used during programming and the programmed threshold voltage of the cell.

公开(公告)号：EP0745257A1

公开(公告)日：1996-12-04

申请号：EP95943771.0

申请日：1995-12-08

申请人： NATIONAL SEMICONDUCTOR CORPORATION

发明人： BERGEMONT, Albert ,  CHI, Min-hwa

IPC分类号： G11C11

CPC分类号： G11C11/5628 ,  G11C11/5621 ,  G11C11/5635 ,  G11C2211/5625

摘要： Multiple logic levels can be programmed into a single EPROM or FLASH memory cell by applying one of a corresponding number of programming voltages to the control gate of a memory cell that has a punch-through current during programming. During programming, the punch-through current forms substrate hot electrons which, in addition to the channel hot electrons, accumulate on the floating gate. By utilizing the punch-through hot electrons, a much lower control gate voltage can be utilized during programming. More importantly, however, once the channel hot electrons cease to exist, the punch-through hot electrons and holes converge to a stable charge that is related to the control gate voltage used during programming and the programmed threshold voltage of the cell.

公开(公告)号：EP0764329B1

公开(公告)日：2001-06-06

申请号：EP96912630.9

申请日：1996-04-08

申请人： National Semiconductor Corporation

发明人： BERGEMONT, Albert ,  CHI, Min-hwa

IPC分类号： G11C11/56

CPC分类号： G11C16/0491 ,  G11C11/5621 ,  G11C11/5628 ,  G11C11/5635 ,  G11C2211/5622

摘要： Multiple logic levels can be simultaneously programmed into any combination of memory cells in a column of an alternate-metal virtual-ground (AMG) EPROM or flash memory array by applying one of a corresponding number of programming voltages to the word lines that correspond with the cells to be programmed. In the present invention, the memory cells in the array form a punchthrough current during programming which, in turn, leads to the formation of an increased number of substrate hot electrons. By utilizing the substrate hot electrons formed from the punchthrough current in addition to the channel hot electrons, much lower control gate voltages can be utilized during programming.

公开(公告)号：EP0846339A1

公开(公告)日：1998-06-10

申请号：EP96916822.0

申请日：1996-05-24

申请人： National Semiconductor Corporation

发明人： BERGEMONT, Albert ,  CHI, Min-hwa ,  HAGGAG, Hosam

IPC分类号： H01L27 ,  H01L31

CPC分类号： H01L31/1105 ,  H01L27/105 ,  Y10S148/124

摘要： A capacitor coupled contactless imager structure and a method of manufacturing the structure results in a phototransistor that structure includes an N-type collector region formed in P-type semiconductor material. A P-type base region is formed in the collector region. An n-doped polysilicon emitter contact is formed in contact with the surface of the P-type base region such that an n+ epitaxial region is formed in the base region as the emitter of the phototransistor. Silicon dioxide separates the poly1 emitter content and exposed surfaces at the base region from a layer of poly2 about 3000-4000Å thick that partially covers the base region; the gates of the CMOS peripheral devices are also poly2. The poly2 over the base region serves as a base coupling capacitor and a row conductor for the imager structure. The thickness of the poly2 capacitor plate allows it to be doped utilizing conventional techniques and silicided to improve the RC constant.

公开(公告)号：EP0764329A1

公开(公告)日：1997-03-26

申请号：EP96912630.0

申请日：1996-04-08

申请人： National Semiconductor Corporation

发明人： BERGEMONT, Albert ,  CHI, Min-hwa

IPC分类号： G11C11 ,  G11C16

CPC分类号： G11C16/0491 ,  G11C11/5621 ,  G11C11/5628 ,  G11C11/5635 ,  G11C2211/5622

摘要： Multiple logic levels can be simultaneously programmed into any combination of memory cells in a column of an alternate-metal virtual-ground (AMG) EPROM or flash memory array by applying one of a corresponding number of programming voltages to the word lines that correspond with the cells to be programmed. In the present invention, the memory cells in the array form a punchthrough current during programming which, in turn, leads to the formation of an increased number of substrate hot electrons. By utilizing the substrate hot electrons formed from the punchthrough current in addition to the channel hot electrons, much lower control gate voltages can be utilized during programming.