1、JEDEC PUBLICATION Test Procedure for the Measurement of Terrestrial Cosmic Ray Induced Destructive Effects in Power Semiconductor Devices JEP151 SEPTEMBER 2015 JEDEC SOLID STATE TECHNOLOGY ASSOCIATION NOTICE JEDEC standards and publications contain material that has been prepared, reviewed, and appr
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9、JEDEC Solid State Technology Association 3103 North 10th Street Suite 240 South Arlington, VA 22201-2107 or refer to www.jedec.org under Standards-Documents/Copyright Information. JEDEC Publication No. 151 -i- Test Procedure for the Measurement of Terrestrial Cosmic Ray Induced Destructive Effects i
10、n Power Semiconductor Devices Contents 1 Scope 1 2 Terms and definitions 2 3 Beam requirements 4 3.1 Beam characteristics 5 3.2 Beam flux . 5 3.3 Acceleration factor . 5 4 Test Set Up . 6 4.1 Exposing devices to the nucleon beam 6 4.2 Application of voltage and temperature to the DUTs. . 7 4.3 Detec
11、tion of failures of the DUTs during nucleon irradiation . 7 4.4 Measuring the fluence to fail . 7 5 Test Procedure . 8 5.1 Test plan generation . 8 5.2 Choosing beam intensity and stressor (voltage, temperature) . 8 5.3 Sample selection 8 5.4 Device preparation . 8 5.5 Evaluation of Device Failure R
12、ates corresponding to cosmic radiation at sea level . 9 6 Reporting Requirements . 10 Annex A (informative) References 11 Annex B (informative) Example of an experimental set up .12 Annex C (informative) Example test plan .14 JEDEC Publication No. 151 -ii- JEDEC Publication No. 151 Page 1 Test Proce
13、dure for the Measurement of Terrestrial Cosmic Ray Induced Destructive Effects in Power Semiconductor Devices (From JEDEC Board Ballot JCB-15-31, formulated under the cognizance of JC-14.1 Subcommittee on Silicon Devices Reliability Qualification and Monitoring.) 1 Scope The main reason for accelera
14、ted testing is the requirement for power electronic devices for high reliability, according to the respective application, and, therefore, to attain very low failure rates. Without accelerated testing any experimental validation of such low failure rates would be impossible. Power electronic devices
15、 that are vulnerable to terrestrial cosmic radiation include power MOSFETs and JFETs, power diodes and IGBTs (Insulated Gate Bipolar Transistors), which are usually employed for power switching and power conversion. They also include GTOs (Gate Turn-Off Thyristors) and Thyristors. Power devices may
16、be with or without control logic and the may be components of integrated circuit. The maximum rated blocking voltage is higher than 300V (see note 2). Power devices may be based on Si, SiC and GaN technologies. This test method defines the requirements and procedures for terrestrial destructive (see
17、 note 1) single-event effects (SEE) for example, single-event breakdown (SEB), single-event latch-up (SEL) and single-event gate rupture (SEGR) testing . It is valid when using an accelerator, generating a nucleon beam of either Mono-energetic protons or mono-energetic neutrons of at least 150 MeV e
18、nergy, or Neutrons from a spallation spectrum with maximum energy of at least 150 MeV This test method does not apply to testing that uses beams with particles heavier than protons. This specific choice of nucleon beam energies is stipulated by the mechanism of power device failure due to terrestria
19、l cosmic radiation. Terrestrial cosmic rays 4 result from extended air showers created by the collision of highly energetic particles of the primary (galactic) cosmic radiation and consist mostly of photons and electrons, muons, pions and nucleons, i.e., protons and neutrons. At sea level about 95%
20、of the strongly interacting particles are neutrons. For SEB to occur in a power device, e.g. a power diode, a nuclear collision between a neutron or proton and a silicon nucleus has to create highly-ionizing spallation fragments which in turn will generate a dense plasma of electron-hole pairs withi
21、n the semiconductor material. If the local plasma density is high enough this will initiate massive carrier multiplication by impact ionization. Resembling discharge in gases, a “streamer” will sweep through the device which will be filled with carriers and short-circuited, as a consequence. Thermal
22、 destruction of the power device might ensue 5. This mechanism is in contrast to the failure modes in microelectronic storage devices, SRAMs or DRAMs, where SEU are related to the radiation-induced charging or discharging of storage cells, and which are non-destructive. JEDEC Publication No. 151 Pag
23、e 2 1 Scope (contd) Accordingly, nucleon beam properties for accelerated testing against Soft Errors 6, which is described in JEDEC Standard JESD89, are different from those that have to be employed for accelerated testing of SEB/SEGR in power devices. Specifically, highly ionizing spallation fragme
24、nt from the silicon-nucleon collision are required to set off a streamer-like discharge. This process is strongly dependent on the applied voltage but also, the primary nucleon has to have an energy that is significantly higher than that for SEU testing. As borne out by experiment, the cross-section
25、 for SEB in power devices is significantly reduced below 150MeV for the range of typical application voltages. If mono-energetic beams are to be employed for the purpose of accelerated testing, therefore, a minimum energy of 150 MeV has to be ensured to assume worst-case conditions for the terrestri
26、al radiation environment. NOTE 1 This test method addresses a separate risk than does JESD89 tests for non-destructive SEE due to cosmic radiation effects on terrestrial applications. NOTE 2 The basic failure mechanism 3 stipulates the electric field-enhanced carrier multiplication from an initial c
27、harge deposition by a nucleon-nucleus collision fragment. The initial charge for this process is, in general, much lower as compared to high-LET heavy-ion-induced charge. Massive charge multiplication as a root cause for device failure is therefore limited to power devices of high blocking voltage.
28、Due to thick active substrates layers of these devices of many carrier mean free path lengths along with high internal electric field strengths carrier multiplication is significant also for relatively low induced carrier densities. As borne out by experience, a minimum nominal blocking voltage of 3
29、00 V is required for terrestrial cosmic radiation to cause device failure. For devices of lower voltage rating, massive charge generation by avalanche multiplication is less effective, even for high internal electric field strengths, due to limited substrate thickness. 2 Terms and definitions The fo
30、llowing are the terms included in the body of the text. ALARA principle: Acronym for “As Low As Reasonably Achievable”. NOTE This principle in radiation protection states that exposure to ionizing radiation should be kept as low as possible, even lower than prescribed by legal requirements, if this
31、is achievable. CR: cosmic ray cross section: The number of failures per unit fluence for a given device. NOTE If one can assume that the depth of the sensitive volume is small compared to its lateral dimensions, the SEE cross section () can be calculated as follows: number of failures = fluence The
32、recommended cross-section units are cm2/device. DUT: Device under test. FIT: failure-in-time, 1 FIT corresponding to 1 failure in 109device-hours. JEDEC Publication No. 151 Page 3 2 Terms and difinitions (contd) fluence: The number of nucleons incident on a surface during a given period of time, div
33、ided by the area of the surface. flux: The time rate of flow of nucleons incident on a surface, divided by the area of that surface. Note: There are different methods to measure the flux value. All methods generating data according to the definition are viable without any further limitation. effecti
34、ve LET (for particle radiation) LET( ): The linear energy transfer (LET) modified to account for the change in total energy transferred from an incident ion as it traverses a sensitive volume when the path of the ion is not normal to the irradiated surface of that volume. NOTE 1 Cosine dependence ma
35、y be applicable for this modification. Caution must be used; see JESD57, Annex B. LET( ) = LET(0) / cos where is the angle of incidence of the ion (i.e., the angle between the ion path and the normal at the point of incidence). NOTE 2 Many modern devices do not follow the above equation, so the expe
36、rimenter may have to determine the LET( ) from the topology of a particular device. NOTE 3 The equation in note 1 is valid only when the depth of the sensitive volume is less than the other two dimensions in the rectangular parallelepiped (RPP) model. monitor calibration factor: The absolute number
37、of nucleons per area per beam detector pulse Note 1 sometimes also called pulse price, detector response or correlation factor sensitive area: An area, or multiple areas, of a device from which induced charge can be collected, in such a manner as to proceed SEE. sensitive volume: A region, or multip
38、le regions, of a device from which induced charge can be collected, in such a manner as to proceed SEE. single-event burnout (SEB): A single-ion-induced condition that causes a localized high-current state, which can result in catastrophic device failure, and is normally characterized by a significa
39、nt increase in drain current that exceeds the manufacturers rated drain leakage current. single-event gate rupture (SEGR): An event in which a single energetic-particle strike results in a breakdown and subsequent conducting path through the gate oxide of a MOSFET. NOTE SEGR is manifested by an incr
40、ease in gate leakage current and can result in either the degradation or the complete failure of the device. single-event effect (SEE): The measurable effect in semiconductor devices due to single-event phenomena and includes, SEB, SEL. JEDEC Publication No. 151 Page 4 2 Terms and difinitions (contd
41、) single-event latch up (SEL): An abnormal high-current state in a device caused by the passage of a single energetic particle through sensitive regions of the device structure and resulting in the loss of device functionality. NOTE SEL may cause permanent damage to the device. If the device is not
42、permanently damaged, power cycling of the device (off and back on) is necessary to restore normal operation. single-event transient (SET): A momentary voltage excursion (voltage spike) at an external terminal of the DUT, caused by the passage of a single energetic particle. single-event upset (SEU):
43、 An event that induces a data error or upset in which the state of a latch or memory cell is reversed (one to zero, or vice versa). terrestrial geographical elevation: elevation up to 18 km above sea level NOTE The upper level of 18km is defined by the maximum of the “Pfotzner Curve” 1 3 Beam requir
44、ements When performing single-event effects testing, the user has the ultimate responsibility for assuring that the beam conditions are correct. One of two types of beams can be used: Mono-energetic proton or neutron beams, or Neutron beams with spallation energy spectrum. It is important to charact
45、erize the beam energy, diameter and angular spread. Second, it is important to measure the nucleon flux and the spatial uniformity of the beam. Neutron beams with and adequate spallation energy spectrum (see 3.1) are preferred over mono-energetic nucleon beams due to their resemblance to the natural
46、 terrestrial radiation environment. Sources of mono-energetic neutron beams, in general, have lower intensity than corresponding mono-energetic proton beams or neutron spallation sources. Therefore, mono-energetic neutrons do not offer any specific advantages and will usually not be employed in a pr
47、actical SEB test. Mono-energetic proton beams, on the other hand, have the distinct advantage that they are by far more intense than any existing neutron spallation source. The corresponding acceleration factors for SEB testing allow the measurement of very low failure rates with adequate confidence
48、. Depending on the specific application, reliability requirements for power devices stipulate values as low as 0.1 FIT (automotive) to 100 FIT (traction) per device for the failure rate. In order to test for these low values within reasonable time (e.g., 30 minutes for a single specific setting of s
49、tressors, i.e., bias voltage and temperature) an acceleration factor of 1E11 1E9 would be required, which translates into an integrated beam intensity of about 5E8-5E6/cmsec. This is clearly well beyond, or just at, the performance of any available neutron spallation source. JEDEC Publication No. 151 Page 5 3 Beam requirements (contd) Currently, the only viable solution to this impasse is the use of mono-energetic proton beams which are readily available and accessible for industrial users 8. On the other hand, it has to
