Memory transistor

Claim 2

A memory transistor comprising, a solid state switch means capable of assuming one of two states dependent on the polarity of a bias signal which is to be applied thereto, a photovoltaic-ferroelectric means for storing information regarding the polarity of said bias signal, which information is stored in the form of a remanent polarization in one of two possible directions, illumination means for illuminating said photovoltaic-ferroelectric means when it is desired to generate said bias signal, and means for applying said generated bias signal to said solid state switch means.

Claim 3

The memory transistor of claim 1 wherein said switch means is a MOSFET transistor means and wherein said photovoltaic-ferroelectric means is connected between the gate and source of the transistor means.

Claim 4

The memory transistor of claim 2 wherein a voltage source and load resistor are connected between the drain and source of the transistor means.

Claim 5

The memory transistor of claim 2 further including a switch means for isolating said transistor means from a voltage which is applied to said photovoltaic-ferroelectric means to create said remanent polarization.

Claim 6

A restorable memory comprising, a flip-flop comprised of at least two switching elements, means for applying biasing voltages of opposite polarities to said switching elements to switch said flip-flop into one of its states or the other, a pair of photovoltaic-ferroelectric elements, each element being connected to a said switching element so that the biasing voltage applied to said switching element creates a remanent polarization in said photovoltaic-ferroelectric element in a direction which will produce a voltage of the same polarity as said biasing voltage when said photovoltaic-ferroelectric element is illuminated, and means for illuminating said photovoltaic-ferroelectric element when power to said flip-flop is lost whereby biasing voltages are applied by said photovoltaic-ferroelectric elements to said solid state elements to return the flip-flop to the state which it was in when said power was lost.

Claim 7

A restorable memory comprising, a flip-flop comprised of at least two switching elements, means for applying biasing voltages of opposite polarities to said switching elements to switch said flip-flop into one of its states or the other, a pair of photovoltaic-ferroelectric elements, each element being connected to a said switching element so that the biasing voltage applied to said switching element creates a remanent polarization in said photovoltaic-ferroelectric element in a direction which will produce a voltage of the same polarity as said biasing voltage when said photovoltaic-ferroelectric element is illuminated, and means for illuminating said photovoltaic-ferroelectric element when power to said flip-flop is lost whereby biasing voltages are applied by said photovoltaic-ferroelectric elements to said solid state elements to return the flip-flop to the state which it was in when said power was lost.

Claim 8

The restorable memory of claim 5 wherein said flip-flop is a cross-coupled MOSFET flip-flop.

Claim 9

The memory transistor of claim 2 wherein said MOSFET transistor means and said photovoltaic-ferroelectric means are part of an integrated structure, said photovoltaic-ferroelectric means overlying the gate of said MOSFET transistor means but being separated from it by an insulating dielectric layer.

Claim 10

The memory transistor of claim 7 wherein the gate electrode of said MOSFET transistor means and one electrode of said photovoltaic-ferroelectric means are common.