Method and system for improving the radiation tolerance of floating gate memories
A method of improving radiation tolerance of floating gate memories is provided herein. Floating gate memories can include a floating gate transistor or a block of floating gate transistors. A floating gate transistor can include a semiconductor region, a source region, a drain region, a floating gate region, a tunnel oxide region, an oxide-nitride-oxide region, and a control gate region. A floating gate transistor or block of floating gate transistors can be written to multiple times in order to accumulate charge on one or more floating gate regions in accordance with an embodiment of the invention. When exposed to radiation, a floating gate region can retain its charge above a certain voltage threshold. A block of floating gate transistors can communicate with an external device where the external device can read a state of the block of floating gate transistors in accordance with an embodiment of the invention.
1. A system for improving radiation tolerance comprising:
a control section comprising a non-transitory storage medium including machine-readable instructions comprising;
a first plurality of machine-readable instructions that operates the control section to write to a floating gate transistor a plurality of times, wherein each write operation comprises applying a bias in a semiconductor substrate region of said floating gate transistor that induces a tunneling effect that causes an amount of charge to gather on a floating gate region of said floating gate transistor;
a second plurality of machine-readable instructions are designed or constructed to operate the control section to control a radiation source to irradiate said floating gate transistor at a predetermined radiation threshold; and
a third plurality of machine-readable instructions are designed or constructed to operate the control section to determine if data on said floating gate transistor is above or below a predetermined data corruption threshold;
wherein said first plurality of machine-readable instructions are designed or constructed to operate the control section to remove charge from said floating gate transistor and write to said floating gate transistor an increased number of said plurality of times until said data is maintained above said predetermined data corruption threshold.
2. The system of improving radiation tolerance of claim 1 , wherein said predetermined radiation threshold is based on a predetermined radiation environment.
3. The system of improving radiation tolerance of claim 1 , wherein if said data on said floating gate transistor is above said predetermined data corruption threshold, then a radiation-resistant state is achieved, wherein if said data on said floating gate transistor is below said predetermined data corruption threshold, then said radiation-resistant state is not achieved.
4. The system of improving radiation tolerance of claim 1 , wherein said predetermined data corruption threshold comprises a charge state threshold for the floating gate transistor above a predetermined charge state necessary to prevent charge loss below a predetermined threshold in the charge storage system comprising a logical data corruption level during the irradiation of said floating gate transistor at said predetermined radiation threshold.