RADIATION DETECTING DEVICE AND METHOD OF OPERATING

• US 20130001428A1
• Filed: 09/13/2012
• Published: 01/03/2013
• Est. Priority Date: 05/19/2009
• Status: Active Grant

• Current Assignee: Infineon Technologies Batam PT (Infineon Technologies AG)
• Original Assignee: Spansion LLC (Infineon Technologies AG)
• Inventors: McCarthy, Michael
• Granted Patent: US 8,581,203 B2
• Time in Patent Office: Days
• US Class Current: 250/371
• CPC Class Codes: H01L 29/792 with charge trapping gate insulator, e.g. MNOS-memory transistors

Abstract

A method of operating a radiation-detecting device includes charging a first charge storage region of a charge storage structure to place a first charge value at the first charge storage region, and charging a second charge storage region of the charge storage structure to place a second charge value at the second charge storage region. The method further includes conducting a first read operation to determine a change in the first charge value at the first charge storage region at a first time after charging the first charge storage region, and determining a first radiation flux value for an environment containing the charge storage structure based on the change in the first charge value at the first time.

Claims

1. A method of operating a radiation-detecting device comprising:

charging a first charge storage region of a charge storage structure to place a first charge value at the first charge storage region;

charging a second charge storage region of the charge storage structure to place a second charge value at the second charge storage region;

conducting a first read operation to determine a change in the first charge value at the first charge storage region at a first time after charging the first charge storage region; and

determining a first radiation flux value for an environment containing the charge storage structure based on the change in the first charge value at the first time.

2. The method of claim 1, further comprising reporting the first radiation flux.

3. The method of claim 1, wherein charging a first charge storage region is conducted at a first time.

4. The method of claim 3, further comprising charging the first charge storage region at a third charge value at a third time after conducting the first read operation.

5. The method of claim 4, further comprising conducting a third read operation to determine a change in the third charge value at the first charge storage region after charging the first charge storage region at the third charge value.

6. The method of claim 5, further comprising determining a third radiation flux value for the environment based on the change in the third charge value at the first charge storage region.

7. The method of claim 5, wherein the third read operation is conducted at a fourth time.

8. The method of claim 4, further comprising:

comparing the first radiation flux value to a threshold radiation flux value; and

identifying a radiation flux value indicator based on the comparison.

9. The method of claim 8, wherein the third charge value is based upon the radiation flux value indicator.

10. The method of claim 1, further comprising conducting a second read operation to determine a change in the second charge value at the second charge storage region at a second time after charging the second charge storage region.

11. The method of claim 10, wherein the second time is different than the first time.

12. The method of claim 10, further comprising determining a second radiation flux value for the environment based on the change in the second charge value for the second time.

13. The method of claim 12, further comprising:

comparing the first radiation flux value to the second radiation flux value; and

identifying a radiation flux value indicator based on the comparison.

14. The method of claim 13, further comprising:

comparing the radiation flux value indicator to a threshold radiation flux value; and

generating an alert signal wherein the radiation flux value indicator exceeds the threshold radiation flux value.

15. A radiation-detecting device comprising:

a first multi-bit storage cell at a substrate comprising;

a first charge storage structure comprising a first nitride-containing layer overlying a first channel region at the substrate;

a first conductive gate layer overlying the first charge storage structure;

a first source/drain region adjacent the first channel region, wherein a portion of the first source/drain region underlies a portion of the first charge storage structure and a first bit storage region for storing information, wherein the first bit storage region is between the first source/drain region and the first conductive gate layer;

a second source/drain region adjacent the first channel region, wherein a portion of the second source/drain region underlies a portion of the first charge storage structure and a second bit storage region for storing information, wherein the second bit storage region is between the second source/drain region and the first conductive gate layer; and

a second multi-bit storage cell at the substrate comprising;

a second charge storage structure comprising a second nitride-containing layer overlying a second channel region at the substrate, wherein the second nitride-containing layer has a geometry that is significantly different than the first nitride-containing layer and configured to hold a significantly different amount of charge than the first nitride-containing layer of the first charge storage structure;

a second conductive gate layer overlying the second charge storage structure;

a third source/drain region adjacent the second channel region, wherein a portion of the third source/drain region underlies a portion of the second charge storage structure and a third bit storage region for storing information, wherein the third bit storage region is between the third source/drain region and the second conductive gate layer; and

a fourth source/drain region adjacent the second channel region, wherein a portion of the fourth source/drain region underlies a portion of the second charge storage structure and a fourth bit storage region for storing information, wherein the fourth bit storage region is between the fourth source/drain region and the second conductive gate layer.

16. The device of claim 15, wherein the first bit storage region and second bit storage region are contained within the first nitride-containing layer of the first charge storage structure.

17. The device of claim 15, wherein the second nitride-containing layer of the second charge storage structure has an average thickness that is greater than an average thickness of the nitride-containing layer of the first charge storage structure.

18. The device of claim 15, wherein the second multi-bit storage cell comprises a second charge storage capacity that is significantly greater than a first charge storage capacity of the first multi-bit storage cell.

19. The device of claim 15, further comprising a thermalizing layer overlying the first charge storage structure.

20. The device of claim 19, wherein the thermalizing layer overlies the second charge storage structure.