Neutron testing of the ISL7119RH hardened dual comparator Nick van Vonno Intersil Corporation 3 July 2013 Revision 0 Table of Contents 1. Introduction 2. Part Description 3. Test Description 3.1 Irradiation facility 3.2 Characterization equipment 3.3 Experimental Matrix 4 Results 4.1 Test results 4.2 Variables data 5 Discussion and conclusion 6 Appendices 7 Document revision history 1. Introduction This report summarizes results of 1 MeV equivalent neutron testing of the ISL7119RH dual comparator. The test was conducted in order to determine the sensitivity of the part to the displacement damage caused by the neutron environment. Neutron fluences ranged from 5 x 1011 n/cm2 to 1 x 1014 n/cm2 in an approximately logarithmic sequence. This project was carried out in collaboration with Honeywell Aerospace (Clearwater, FL), and their support is gratefully acknowledged. 2: Part Description The ISL7119RH and ISL7119EH are radiation hardened, high speed, dual voltage comparators fabricated on a single monolithic chip. They are designed to operate over a wide dual supply voltage range as well as a single 5V logic supply and ground. The open collector output stage facilitates interfacing with a variety of logic devices and has the ability to drive relays and lamps at output currents up to 25mA. The ISL7119RH and ISL7119EH are fabricated on our dielectrically isolated Rad-hard Silicon Gate (RSG) process, which provides highly reliable performance in the natural space environment. Specifications for radiation hardened QML devices are controlled by the Defense Logistics Agency Land and Maritime (DLA). Detailed electrical specifications for the ISL7119RH and ISL7119EH are contained in SMD 5962-07215. The ISL7119RH is implemented in the Intersil RSG process, which is a complementary bipolar/CMOS flow using dielectrically isolated (DI) substrates. The process is used for a range of hardened operational amplifiers and other analog and power management parts. The DI technology 1 enables vertical NPN and PNP devices, unlike the vertical NPN/lateral PNP combination used in commercial junction isolated processes. The vertical PNP device improves AC performance and total dose hardness, while the DI substrate eliminates latchup by either electrical or SEE conditions. The process is in volume production under MIL-PRF-38535 certification in the Palm Bay, Florida Intersil wafer fabrication facility. 3: Test Description 3.1 Irradiation Facilities Neutron irradiation was performed by the Honeywell team at the Fast Burst Reactor facility at White Sands Missile Range (White Sands, NM), which provides a controlled 1MeV equivalent neutron flux. Parts were tested in an unbiased configuration with all leads open. As neutron irradiation activates many of the elements found in a packaged integrated circuit, the parts exposed at the higher neutron levels required (as expected) significant ‘cooldown time’ before being shipped back to Palm Bay for electrical testing. 3.2 Characterization equipment and procedures Electrical testing was performed before and after irradiation using the Intersil production automated test equipment (ATE). All electrical testing was performed at room temperature. 3.3 Experimental matrix Testing proceeded in general accordance with the guidelines of MIL-STD-883 Test Method 1017. The experimental matrix consisted of five samples irradiated at 5 x 1011 n/cm2, five samples irradiated at 2 x 1012 n/cm2, five samples irradiated at 1 x 1013 n/cm2 and five samples irradiated at 1 x 1014 n/cm2. Three control units were used. 4: Results 4.1 Test results Neutron testing of the ISL7119RH is complete and the results are reported in the balance of this report. It should be realized when reviewing the data that each neutron irradiation was made on a different 5-unit sample; this is not total dose testing, where the damage is cumulative. 4.2 Variables data The plots in Figs. 1 through 20 show data plots for key parameters before and after irradiation to each level. The plots show the average, minimum and maximum of each parameter for each of the two channels as a function of neutron irradiation. 2 Positive power supply current, mA 14.0 12.0 10.0 Ch 1 Median Ch 1 Min Ch 1 Max Ch 2 Median Ch 2 Min Ch 2 Max Spec low Spec high 8.0 6.0 4.0 2.0 0.0 Pre-rad 1.00E+11 1.00E+12 1.00E+13 Neutron fluence, 1.00E+14 n/cm2 Fig. 1: ISL7119RH positive power supply current as a function of neutron irradiation, showing the mean, minimum and 11 2 12 2 13 maximum of the populations at each level. Sample size was 5 for each cell (5 x 10 n/cm , 2 x 10 n/cm , 1 x 10 2 14 2 n/cm and 1 x 10 n/cm ), with three control units. The post-irradiation SMD limit is 12.0mA; the 2.0mA value is an ATE limit. Negative power supply current, mA 0.0 -1.0 -2.0 -3.0 -4.0 -5.0 -6.0 Pre-rad 1.00E+11 1.00E+12 Ch 1 Median Ch 1 Min Ch 1 Max Ch 2 Median Ch 2 Min Ch 2 Max Spec low Spec high 1.00E+13 Neutron fluence, 1.00E+14 n/cm2 Fig. 2: ISL7119RH negative power supply current as a function of neutron irradiation, showing the mean, minimum and 11 2 12 2 13 maximum of the populations at each level. Sample size was 5 for each cell (5 x 10 n/cm , 2 x 10 n/cm , 1 x 10 2 14 2 n/cm and 1 x 10 n/cm ), with three control units. The post-irradiation SMD limit is -5.0.0mA; the -0.6mA value is an ATE limit. 3 1.0 Output saturation voltage, V 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.0 1.00E+11 Pre-rad 1.00E+12 Ch 1 Median Ch 1 Min Ch 1 Max Ch 2 Median Ch 2 Min Ch 2 Max Spec low Spec high 1.00E+13 Neutron fluence, 1.00E+14 n/cm2 Fig. 3: ISL7119RH output saturation voltage as a function of neutron irradiation, showing the mean, minimum and 11 2 12 2 13 maximum of the populations at each level. Sample size was 5 for each cell (5 x 10 n/cm , 2 x 10 n/cm , 1 x 10 2 14 2 n/cm and 1 x 10 n/cm ), with three control units. The post-irradiation SMD limit is 0.65V maximum. 25.0 Output leakage current, µA 20.0 15.0 10.0 5.0 0.0 -5.0 Ch 1 Median Ch 1 Min -10.0 Ch 1 Max Ch 2 Median -15.0 Ch 2 Min Ch 2 Max -20.0 Spec low Spec high -25.0 1.00E+11 Pre-rad 1.00E+12 1.00E+13 Neutron fluence, 1.00E+14 n/cm2 Fig. 4: ISL7119RH output leakage current as a function of neutron irradiation, showing the mean, minimum and 11 2 12 2 13 maximum of the populations at each level. Sample size was 5 for each cell (5 x 10 n/cm , 2 x 10 n/cm , 1 x 10 2 14 2 n/cm and 1 x 10 n/cm ), with three control units. The post-irradiation SMD limits are -20.0µA to 20.0µA. 4 Input offset voltage, Vcm=3V, mV 10.0 8.0 6.0 4.0 Ch 1 Median Ch 1 Min Ch 1 Max Ch 2 Median Ch 2 Min Ch 2 Max Spec low Spec high 2.0 0.0 -2.0 -4.0 -6.0 -8.0 -10.0 Pre-rad 1.00E+11 1.00E+12 1.00E+13 Neutron fluence, 1.00E+14 n/cm2 Fig. 5: ISL7119RH input offset voltage as a function of neutron irradiation, common mode voltage 3.0V, showing the 11 2 12 mean, minimum and maximum of the populations at each level. Sample size was 5 for each cell (5 x 10 n/cm , 2 x 10 2 13 2 14 2 n/cm , 1 x 10 n/cm and 1 x 10 n/cm ), with three control units. The post-irradiation SMD limits are -8.0mV to 8.0mV. Input offset voltage, Vcm=12V, mV 10.0 8.0 6.0 4.0 Ch 1 Median Ch 1 Min Ch 1 Max Ch 2 Median Ch 2 Min Ch 2 Max Spec low Spec high 2.0 0.0 -2.0 -4.0 -6.0 -8.0 -10.0 Pre-rad 1.00E+11 1.00E+12 1.00E+13 Neutron fluence, 1.00E+14 n/cm2 Fig. 6: ISL7119RH input offset voltage as a function of neutron irradiation, common mode voltage 12.0V, showing the 11 2 12 mean, minimum and maximum of the populations at each level. Sample size was 5 for each cell (5 x 10 n/cm , 2 x 10 2 13 2 14 2 n/cm , 1 x 10 n/cm and 1 x 10 n/cm ), with three control units. The post-irradiation SMD limits are -8.0mV to 8.0mV. 5 Input offset voltage, Vcm=-12V, mV 10.0 8.0 6.0 4.0 Ch 1 Median Ch 1 Min Ch 1 Max Ch 2 Median Ch 2 Min Ch 2 Max Spec low Spec high 1.00E+13 1.00E+14 2.0 0.0 -2.0 -4.0 -6.0 -8.0 -10.0 Pre-rad 1.00E+11 1.00E+12 Neutron fluence, n/cm2 Fig. 7: ISL7119RH input offset voltage as a function of neutron irradiation, common mode voltage -12.0V, showing the 11 2 12 mean, minimum and maximum of the populations at each level. Sample size was 5 for each cell (5 x 10 n/cm , 2 x 10 2 13 2 14 2 n/cm , 1 x 10 n/cm and 1 x 10 n/cm ), with three control units. The post-irradiation SMD limits are -8.0mV to 8.0mV. Common mode rejection ratio, dB 250 200 150 Ch 1 Median Ch 1 Min Ch 1 Max Ch 2 Median Ch 2 Min Ch 2 Max Spec low Spec high 1.00E+13 1.00E+14 100 50 0 Pre-rad 1.00E+11 1.00E+12 Neutron fluence, n/cm2 Fig. 8: ISL7119RH common mode rejection ratio as a function of neutron irradiation, showing the mean, minimum and 11 2 12 2 13 maximum of the populations at each level. Sample size was 5 for each cell (5 x 10 n/cm , 2 x 10 n/cm , 1 x 10 2 14 2 n/cm and 1 x 10 n/cm ), with two control units. The post-irradiation SMD limits are 80dB to 200dB. 6 Positive bias current, Vcm=3V, nA 4000 3500 3000 Ch 1 Median Ch 1 Min Ch 1 Max Ch 2 Median Ch 2 Min Ch 2 Max Spec high 2500 2000 1500 1000 500 0 Pre-rad 1.00E+11 1.00E+12 1.00E+13 Neutron fluence, 1.00E+14 n/cm2 Fig. 9: ISL7119RH positive bias current as a function of neutron irradiation, common mode voltage 3.0V, showing the 11 2 12 mean, minimum and maximum of the populations at each level. Sample size was 5 for each cell (5 x 10 n/cm , 2 x 10 2 13 2 14 2 n/cm , 1 x 10 n/cm and 1 x 10 n/cm ), with three control units. The post-irradiation SMD limit is 1000nA maximum. Negative bias current, Vcm=3V, nA 4000 3500 3000 Ch 1 Median Ch 1 Min Ch 1 Max Ch 2 Median Ch 2 Min Ch 2 Max Spec high 2500 2000 1500 1000 500 0 Pre-rad 1.00E+11 1.00E+12 1.00E+13 Neutron fluence, 1.00E+14 n/cm2 Fig. 10: ISL7119RH negative bias current as a function of neutron irradiation, common mode voltage 3.0V, showing the 11 2 12 mean, minimum and maximum of the populations at each level. Sample size was 5 for each cell (5 x 10 n/cm , 2 x 10 2 13 2 14 2 n/cm , 1 x 10 n/cm and 1 x 10 n/cm ), with three control units. The post-irradiation SMD limit is 1000nA maximum. 7 Input offset current, Vcm=3V, nA 1000 800 600 Ch 1 Median Ch 1 Min Ch 1 Max Ch 2 Median Ch 2 Min Ch 2 Max Spec low Spec high 400 200 0 -200 1.00E+11 Pre-rad 1.00E+12 1.00E+13 Neutron fluence, 1.00E+14 n/cm2 Fig. 11: ISL7119RH input offset current as a function of neutron irradiation, common mode voltage 3.0V, showing the 11 2 12 mean, minimum and maximum of the populations at each level. Sample size was 5 for each cell (5 x 10 n/cm , 2 x 10 2 13 2 14 2 n/cm , 1 x 10 n/cm and 1 x 10 n/cm ), with three control units. The post-irradiation SMD limits are -150nA to 150nA. Positive bias current, Vcm=12V, nA 4500 4000 3500 3000 Ch 1 Median Ch 1 Min Ch 1 Max Ch 2 Median Ch 2 Min Ch 2 Max Spec high 2500 2000 1500 1000 500 0 1.00E+11 Pre-rad 1.00E+12 1.00E+13 Neutron fluence, 1.00E+14 n/cm2 Fig. 12: ISL7119RH positive bias current as a function of neutron irradiation, common mode voltage 12.0V, showing the 11 2 12 mean, minimum and maximum of the populations at each level. Sample size was 5 for each cell (5 x 10 n/cm , 2 x 10 2 13 2 14 2 n/cm , 1 x 10 n/cm and 1 x 10 n/cm ), with three control units. The post-irradiation SMD limit is 1000nA maximum. 8 Negative bias current, Vcm=12V, nA 5000 4500 4000 3500 Ch 1 Median Ch 1 Min Ch 1 Max Ch 2 Median Ch 2 Min Ch 2 Max Spec high 3000 2500 2000 1500 1000 500 0 Pre-rad 1.00E+11 1.00E+12 1.00E+13 Neutron fluence, 1.00E+14 n/cm2 Fig. 13: ISL7119RH negative bias current as a function of neutron irradiation, common mode voltage 12.0V, showing the 11 2 12 mean, minimum and maximum of the populations at each level. Sample size was 5 for each cell (5 x 10 n/cm , 2 x 10 2 13 2 14 2 n/cm , 1 x 10 n/cm and 1 x 10 n/cm ), with three control units. The post-irradiation SMD limit is 1000nA maximum. Input offset current, Vcm=12V, nA 1600 1400 1200 1000 Ch 1 Median Ch 1 Min Ch 1 Max Ch 2 Median Ch 2 Min Ch 2 Max Spec low Spec high 800 600 400 200 0 -200 -400 Pre-rad 1.00E+11 1.00E+12 1.00E+13 Neutron fluence, 1.00E+14 n/cm2 Fig. 14: ISL7119RH input offset current as a function of neutron irradiation, common mode voltage 12.0V, showing the 11 2 12 mean, minimum and maximum of the populations at each level. Sample size was 5 for each cell (5 x 10 n/cm , 2 x 10 2 13 2 14 2 n/cm , 1 x 10 n/cm and 1 x 10 n/cm ), with three control units. The post-irradiation SMD limits are -150nA to 150nA. 9 Positive bias current, Vcm=-12V, nA 4500 Ch 1 Median Ch 1 Min Ch 1 Max Ch 2 Median 3500 Ch 2 Min Ch 2 Max 3000 Spec high 4000 2500 2000 1500 1000 500 0 Pre-rad 1.00E+11 1.00E+12 1.00E+13 Neutron fluence, 1.00E+14 n/cm2 Fig. 15: ISL7119RH positive bias current as a function of neutron irradiation, common mode voltage -12.0V, showing the 11 2 12 mean, minimum and maximum of the populations at each level. Sample size was 5 for each cell (5 x 10 n/cm , 2 x 10 2 13 2 14 2 n/cm , 1 x 10 n/cm and 1 x 10 n/cm ), with three control units. The post-irradiation SMD limit is 1000nA maximum. Negative bias current, Vcm=-12V, nA 4500 4000 3500 3000 Ch 1 Median Ch 1 Min Ch 1 Max Ch 2 Median Ch 2 Min Ch 2 Max Spec high 2500 2000 1500 1000 500 0 Pre-rad 1.00E+11 1.00E+12 1.00E+13 Neutron fluence, 1.00E+14 n/cm2 Fig. 16: ISL7119RH negative bias current as a function of neutron irradiation, common mode voltage -12.0V, showing 11 2 the mean, minimum and maximum of the populations at each level. Sample size was 5 for each cell (5 x 10 n/cm , 2 x 12 2 13 2 14 2 10 n/cm , 1 x 10 n/cm and 1 x 10 n/cm ), with three control units. The post-irradiation SMD limit is 1000nA maximum. 10 Input offset current, Vcm=-12V, nA 800 700 600 500 Ch 1 Median Ch 1 Min Ch 1 Max Ch 2 Median Ch 2 Min Ch 2 Max 400 300 200 100 0 -100 -200 Pre-rad 1.00E+11 1.00E+12 1.00E+13 Neutron fluence, 1.00E+14 n/cm2 Fig. 17: ISL7119RH input offset current as a function of neutron irradiation, common mode voltage -12.0V, showing the 11 2 12 mean, minimum and maximum of the populations at each level. Sample size was 5 for each cell (5 x 10 n/cm , 2 x 10 2 13 2 14 2 n/cm , 1 x 10 n/cm and 1 x 10 n/cm ), with three control units. The post-irradiation SMD limits are -150nA to 150nA. 250 Open loop gain, dB 200 150 Ch 1 Median Ch 1 Min Ch 1 Max Ch 2 Median Ch 2 Min Ch 2 Max Spec low Spec high 100 50 0 Pre-rad 1.00E+11 1.00E+12 1.00E+13 Neutron fluence, 1.00E+14 n/cm2 Fig. 18: ISL7119RH open-loop gain as a function of neutron irradiation, showing the mean, minimum and maximum of 11 2 12 2 13 2 14 the populations at each level. Sample size was 5 for each cell (5 x 10 n/cm , 2 x 10 n/cm , 1 x 10 n/cm and 1 x 10 2 n/cm ), with three control units. The post-irradiation SMD limit is 74dB minimum; the 200dB value is an ATE limit. 11 Propagation delay, low to high, ns 180 160 140 120 Ch 1 Median Ch 1 Min Ch 1 Max Ch 2 Median Ch 2 Min Ch 2 Max Spec low Spec high 100 80 60 40 20 0 Pre-rad 1.00E+11 1.00E+12 1.00E+13 Neutron fluence, 1.00E+14 n/cm2 Fig. 19: ISL7119RH low to high propagation delay as a function of neutron irradiation, showing the mean, minimum and 11 2 12 2 13 maximum of the populations at each level. Sample size was 5 for each cell (5 x 10 n/cm , 2 x 10 n/cm , 1 x 10 2 14 2 n/cm and 1 x 10 n/cm ), with three control units. The post-irradiation SMD limit is 160ns maximum; the 10ns value is an ATE limit. Propagation delay, high to low, ns 180 160 140 120 Ch 1 Median Ch 1 Min Ch 1 Max Ch 2 Median Ch 2 Min Ch 2 Max Spec low Spec high 100 80 60 40 20 0 1.00E+11 Pre-rad 1.00E+12 1.00E+13 Neutron fluence, 1.00E+14 n/cm2 Fig. 20: ISL7119RH high to low propagation delay as a function of neutron irradiation, showing the mean, minimum and 11 2 12 2 13 maximum of the populations at each level. Sample size was 5 for each cell (5 x 10 n/cm , 2 x 10 n/cm , 1 x 10 2 14 2 n/cm and 1 x 10 n/cm ), with three control units. The post-irradiation SMD limit is 160ns maximum; the 10ns value is an ATE limit. 12 5: Discussion and conclusion This document reports the results of neutron testing of the ISL7119RH dual comparator. Samples were irradiated to levels of 5 x 1011 n/cm2, 2 x 1012 n/cm2, 1 x 1013 n/cm2 and 1 x 1014 n/cm2 with a sample size of five parts per cell. It should again be realized when reviewing the data that each neutron irradiation was made on a different 5-unit sample; this is not total dose testing, where the damage is cumulative. ATE characterization testing was performed before and after the irradiations, and three control units were used to insure repeatable data. Variables data for monitored parameters is presented in Figs. 1 through 20. The 2 x 1012 n/cm2 level is of some interest in the context of recent developments in the JEDEC community, where the discrete component vendor community have signed up for characterization testing (but not for acceptance testing) at this level. The ISL7119RH is not formally designed for neutron hardness. The part is built in a DI complementary bipolar process. These bipolar transistors are minority carrier devices, obviously, and may be expected to be sensitive to displacement damage (DD) at the higher levels. This expectation turned out to be correct. We will discuss the results on a parameter by parameter basis and then draw some conclusions. The positive power supply current (Figs. 1 and 2) showed good stability after 5 x 1011 n/cm2 and 2 x 10 n/cm2, increased after 1 x 1013 n/cm2 irradiation and was out of specification after 1 x 1014 n/cm2 irradiation. This behavior was observed in Channel 2 only; Channel 1 showed good stability to 1 x 1014 n/cm2. The reason for this channel sensitivity effect is unknown. The negative power supply current for both channels showed excellent stability to the highest level. 12 The output saturation voltage (Fig. 3) showed good stability after 5 x 1011 n/cm2, 2 x 1012 n/cm2 and 1 x 1013 n/cm2 irradiation but increased significantly after 1 x 1014 n/cm2 irradiation. The range was also increased at this highest level. The output leakage (Fig. 4) showed good stability at all levels, with a modest increase in range. The input offset voltage (Figs. 5, 6 and 7) for common mode voltages of 3.0V, 12.0V and -12.0V, respectively, showed good stability at all levels. The common mode rejection ratio (Fig. 8) showed good stability at all levels. The positive and negative input bias current (Figs. 9 and 10) for an input common-mode voltage of 3.0V showed good stability after 5 x 1011 n/cm2, 2 x 1012 n/cm2 and 1 x 1013 n/cm2 irradiation but increased significantly after 1 x 1014 n/cm2 irradiation, exceeding the post-irradiation specification limits. The range was also increased at this highest level. These results are consistent with gain degradation of the input differential pair of the comparator. The input offset current (Fig. 11) for an input common-mode voltage of 3.0V also showed good stability after 5 x 1011 n/cm2, 2 x 1012 n/cm2 and 1 x 1013 n/cm2 irradiation but increased significantly after 1 x 1014 n/cm2 irradiation. The range was also increased at this highest level. These results are also consistent with gain degradation of the input differential pair of the comparator, but show good gain matching of both transistors over irradiation. The positive and negative input bias current (Figs. 12 and 13) and the input offset current (Fig. 14) for an input common-mode voltage of 12.0V showed good stability after 5 x 1011 n/cm2, 2 x 1012 n/cm2 and 1 x 1013 n/cm2 irradiation but increased significantly after 1 x 1014 n/cm2 irradiation, exceeding the post- 13 irradiation specification limits. The positive and negative input bias current and input offset current at a common-mode input voltage of -12.0V (Figs. 15, 16 and 17) showed similar behavior. The open-loop gain (Fig. 18) showed good stability at all levels. The low to high and high to low response times (Figs. 19 and 20) showed good stability at all levels. We conclude that the ISL7119RH is capable of post 1 x 1013 n/cm2 operation within the SMD posttotal dose parameters. The part is not capable of post 1 x 1014 n/cm2 operation as parameters such as input bias current and input offset current were well outside the SMD limits; the part did, however, remain functional. 6: Appendices 6.1: Reported parameters. Fig. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Parameter Limit, low Positive power supply current Negative power supply current Output saturation voltage Output leakage current Input offset voltage Input offset voltage Input offset voltage Common mode rejection ratio Positive bias current Negative bias current Input offset current Positive bias current Negative bias current Input offset current Positive bias current Negative bias current Input offset current Open-loop gain LOW to HIGH propagation delay HIGH to LOW propagation delay -20.0 -8.0 -8.0 -8.0 +80 -150.0 -150.0 -150.0 +74 - 7: Document revision history Revision 0 Date 3 July 2013 Pages All Comments Original issue 14 Limit, high Units +12.0 -5.0 +0.65 +20.0 +8.0 +8.0 +8.0 +200 +1000 +1000 +150.0 +1000 +1000 +150.0 +1000 +1000 +150.0 160 160 mA mA V µA mV mV mV dB nA nA nA nA nA nA nA nA nA dB ns ns Notes Vcm=3.0V Vcm=12.0V Vcm=-12.0V Vcm=3.0V Vcm=3.0V Vcm=3.0V Vcm=12.0V Vcm=12.0V Vcm=12.0V Vcm=-12.0V Vcm=-12.0V Vcm=-12.0V