公开(公告)号：DE2329009A1

公开(公告)日：1974-01-17

申请号：DE2329009

申请日：1973-06-07

Applicant: IBM

Inventor： KRICK PAUL JOHN ,  PLESHKO PETER

IPC: G11C19/28 ,  H03K3/02 ,  H03K3/037 ,  H03K3/36 ,  H03K19/02 ,  H03K19/10 ,  H03K19/08

Abstract: A circuit consisting of a pair of bistable resistors connected in series at a node to which current may be applied and from which current may be drawn and having a source of potential connected to each bistable resistor is disclosed. The bistable resistors are oriented physically in the same direction such that current in a given direction which exceeds a threshold and which switches the bistable resistors into a high resistance state can be characterized as the forward direction. Conversely, current in the opposite direction to the given direction which, when it exceeds a threshold, switches the devices from a high resistance state into a low resistance state can be characterized as the backward direction. With appropriately applied potentials to each of the bistable resistors, with one potential more positive than the other, current can be made to flow in the forward and backward directions. In the forward direction, both resistors are switched into or remain in a high resistance or RH state. When current flows in the backward direction through the pair of bistable resistors, they switch into or remain in the low resistance or RL state. By applying the same potentials to the bistable resistors and causing current to flow into or out of the node at which the bistable resistors are connected, it is possible to cause the pair of resistors to assume a low resistance high resistance state and, a high resistance low resistance state, respectively. Thus, by simply controlling the potentials and the direction of current flow through each of the pair of bistable resistors, four, non-volatile, stable states are achievable as opposed to a maximum of two volatile states in similarly arranged tunnel diode circuits, for example. Because the arrangements shown are inexpensive, easy to fabricate and permit high packing densities, circuits such as shift registers which utilize large numbers of similarly arranged logic circuits are most attractive. In addition, the nanosecond switching speeds available in bistable resistors make them superior to other known switching devices of slower switching speed. A shift register circuit incorporating three of the four non-volatile, stable states available with the logic circuits is also disclosed. The shift register utilizes a low resistance-high resistance state to represent a binary "one" and a high resistance-high resistance state and a high resistance-low resistance state to represent a binary "zero.

公开(公告)号：DE2363089A1

公开(公告)日：1974-07-04

申请号：DE2363089

申请日：1973-12-19

Applicant: IBM

Inventor： GAENSSLEN FRITZ HEINRICH ,  KRICK PAUL JOHN

IPC: G11C11/405 ,  G11C11/403 ,  G11C11/404 ,  H01L21/8242 ,  H01L27/092 ,  H01L27/108 ,  G11C11/24

Abstract: A semiconductor two device memory cell is disclosed in which the two devices are complementary. The cell is best implemented in the integrated circuit environment and may be fabricated using well known non-complementary fabrication techniques. The cell incorporates a floating region or substrate - within - a - substrate on which charge is stored in different amounts to achieve different potentials on the region thereby controlling, in one mode, the threshold of a field effect transistor of which the floating region forms a part. In a different mode, the floating region or substrate forms a drain or source region for a switching transistor which is formed in its own substrate. The latter substrate, which is formed from a semiconductor chip or wafer, besides forming the channel region of the switching transistor acts as a source for a sensing transistor which is formed by a region of opposite conductivity type in the floating region, the floating region and the substrate itself. The floating region is charged to one of two potentials when the floating region is a drain or source of the switching transistor and, the amount of current flow is controlled by the potential on the floating region when it operates as the substrate for the sensing transistor.