AT89C51ED2-SMSIM ATMEL Corporation, AT89C51ED2-SMSIM Datasheet - Page 11

• Manufacturer Part Number: AT89C51ED2-SMSIM
• Description: 8-bit Flash Microcontroller
• Manufacturer: ATMEL Corporation

AT89C51RD2 / AT89C51ED2 QualPack
4.3.2 Hot Carriers Injection
Test conditions
The test is performed by forcing a high drain bias on the test device (Vds>Vddmax) to accelerate the carriers to the
maximum. At the same time the gate bias (Vgs) is chosen in order to maximize the injection of carriers into the
gate oxide and also the substrate. WLR_B n-channel W/L 0.35um/25um the stress is performed on a number of
transistors, each at a different stress condition Vds,stress and Vgs,stress. For each transistor, the time to reach the
failure criteria (dIdsat/Idsat=10%) is obtained. NMOS is more sensitive to hot carriers compared to PMOS.
Consequently NMOS is the only structure tested.
Measurement
AT568T7 lot 1J0433 has been measured using the WLR_B hot electron structure with standard drain.
NMOS W/L = 25/0.35 um.
Results
HCI 56.8k 1J0433 AT568T7 FAB 5 N-Channel W/L 0.35/25.0um
10% Change in Idsat
1
30,692
y = 5E+16x
0,1
2
R
= 0,9719
0,01
0,001
0,0001
0,2
0,22
0,24
0,26
0,28
0,3
1/Vdd
Conclusion
The extrapolated life time in the worst case conditions (@Vds=Vdd max & Vgs set to maximize substrate current) is
much greater than 0.2 years in DC mode (qualification requirement) which is equivalent to more than 10 years in
AC mode.
Rev. 0 – 2003 July
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