Semiconductor memory device having mis-type transistors
According to one aspect of the present invention, a semiconductor memory device has: a semiconductor layer formed on an insulating film; and a memory cell array including a matrix arrangement of a plurality of memory cells each made up of first and second transistors connected in series, one side of each memory cell being connected to a bit line and the other side of each memory cell being supplied with a reference potential, and according to another aspect of the present invention, a semiconductor memory device manufacturing method includes: forming an oxide layer and a silicon active layer on a semiconductor substrate; forming an element isolation region for separating said silicon active layer into discrete element-forming regions to be substantially flush with said silicon active layer; forming gate electrode of paired two transistors by depositing a gate electrode material on said silicon active layer and patterning it; injecting predetermined ions into a region for forming a diffusion layer in, using said gate electrodes as an ion injection mask; forming said paired transistors by activating the injected ions through a heat process; and forming a first gate line connected to the gate electrode of one of said paired transistors and a second gate line connected to the gate electrode of the other of said paired transistors.
1. A semiconductor memory device comprising:
a semiconductor layer formed on an insulating film;
a memory cell array including a matrix arrangement of a plurality of memory cells each made up of first and second transistors connected in series, one side of each said memory cell being connected to a bit line and the other side of each said memory cell being supplied with a reference potential;
wherein said transistors are MIS-type partially depleted transistors, and;
wherein said first and second transistors have the same conduction type, and wherein a first word line is connected to the gate of said first transistor, and a second word line of the inverse logic paired with said first word line is connected to the gate of said second transistor.
2. A semiconductor memory device according to claim 1 , wherein said word line and said inverse logic word line are controlled to synchronously change in state.
3. A semiconductor memory device according to claim 1 , wherein one of said first word line and said second word line change in state with a predetermined delay time after the other changes in state.
4. A semiconductor memory device according to claim 1 , wherein an inverter is provided between said first word line and said second word line to invert the signal level.
5. A semiconductor memory device according to claim 1 , wherein said transistors having the same conduction type are n-channel type transistors.
6. A semiconductor memory device according to claim 1 , wherein said insulating film and said semiconductor layer are formed on a semiconductor substrate.
7. A semiconductor memory device according to claim 1 , wherein said insulating film and said semiconductor layer are semiconductor layers on a semiconductor substrate.
8. A semiconductor memory device according to claim 1 , wherein each said memory cell made up of said first and second transistors is formed in a region surrounded by an element isolation region.
9. A semiconductor memory device according to claim 8 , wherein said element isolation region is a trench-type element isolation film.
10. A semiconductor memory device comprising:
a semiconductor layer formed on an insulating film;
a memory cell array including a matrix arrangement of a plurality of memory cells each made up of first and second transistors body regions thereof being connected in series, one side of each said memory cell being connected to a bit line and the other side of each said memory cell being supplied with a reference potential,
wherein a threshold value of one of said transistors is controlled by controlling injection or discharge of an electric charge to or from a body region of one of said transistors of a selected memory cell, thereby to store data;
wherein said transistors are MIS-type partially depleted transistors, and;
wherein injection of the electric charge into the body region of said partially-depleted transistor is affected by impact ions generated by a flow of a channel current.