MIL- STD-883F 2004 TEST METHOD STANDARD MICROCIRCUITS - 第116页

MIL-STD-883F METHOD 1018.4 18 June 2004 6 This page i ntenti onally lef t blank

MIL-STD-883F

METHOD 1018.4

18 June 2004

5. SUMMARY

. The following details shall be specified in the applicable acquisition document:

a. The procedure (1, 2, or 3) when a specific procedure is to be used (see 3).

b. The maximum allowable water-vapor content falling within the range of suitability as specified in test method 5005,

5008, or 5010, or general specifications MIL-PRF-38534 or MIL-PRF-38535.

MIL-STD-883F

METHOD 1018.4

18 June 2004

This page intentionally left blank

MIL-STD-883F

METHOD 1019.6

7 March 2003

METHOD 1019.6

IONIZING RADIATION (TOTAL DOSE) TEST PROCEDURE

1. PURPOSE

. This test procedure defines the requirements for testing packaged semiconductor integrated circuits for

ionizing radiation (total dose) effects from a cobalt-60 (

Co) gamma ray source. The testing includes both standard room

temperature irradiation as well as irradiation at elevated temperature. In addition this procedure provides an accelerated

annealing test for estimating low dose rate ionizing radiation effects on devices. This annealing test is important for low

dose-rate or certain other applications in which devices may exhibit significant time-dependent effects. This procedure

addresses only steady state irradiations, and is not applicable to pulse type irradiations. This test may produce severe

degradation of the electrical properties of irradiated devices and thus should be considered a destructive test.

1.1 Definitions

. Definitions of terms used in this procedure are given below:

a. Ionizing radiation effects

. The changes in the electrical parameters of a device or integrated circuit resulting from

radiation-induced charge. These are also referred to as total dose effects.

b. In-flux test

. Electrical measurements made on devices during irradiation exposure.

c. Not in-flux test

. Electrical measurements made on devices at any time other than during irradiation.

d. Remote tests

. Electrical measurements made on devices which are physically removed from the radiation

location.

e. Time dependent effects

. Significant degradation in electrical parameters caused by the growth or annealing or

both of radiation-induced trapped charge after irradiation. Similar effects also take place during irradiation.

f. Accelerated annealing test. A procedure utilizing elevated temperature to accelerate time-dependent effects.

g. Enhanced Low Dose Rate Sensitivity (ELDRS). Used to refer to a part that shows enhanced radiation induced

damage at dose rates below 50 rad(Si)/s.

h. Overtest. A factor that is applied to the specification dose to determine the test dose level that the samples must

pass to be acceptable at the specification level. An ovetest factor of 1.5 means that the parts must be tested at 1.5

times the specification dose.

i. Parameter Delta Design Margin (PDDM). A design margin that is applied to te radiation induced change in an

electrical parameter. For a PDDM of 2 the change in a parameter at a specified dose from the pre-irradiation value

is multiplied by two and added to the post-irradiation value to see if the sample exceeds the post-irradiation

parameter limit. For example, if the pre-irradiation value of Ib is 30 nA and the post-irradiation value at 20 krad(Si)

is 70 nA (change in Ib is 40 nA), then for a PDDM of 2 the post-irradiation value would be 110 nA (30 nA + 2 X 40

nA). If the allowable post-irradiation limit is 100 nA the part would fail.

2. APPARATUS

. The apparatus shall consist of the radiation source, electrical test instrumentation, test circuit board(s),

cabling, interconnect board or switching system, an appropriate dosimetry measurement system, and an environmental

chamber (if required for time-dependent effects measurements or elevated temperature irradiation). Adequate precautions

shall be observed to obtain an electrical measurement system with sufficient insulation, ample shielding, satisfactory

grounding, and suitable low noise characteristics.

2.1 Radiation source

. The radiation source used in the test shall be the uniform field of a

Co gamma ray source.

Uniformity of the radiation field in the volume where devices are irradiated shall be within ±10 percent as measured by the

dosimetry system, unless otherwise specified. The intensity of the gamma ray field of the

Co source shall be known with

an uncertainty of no more than ±5 percent. Field uniformity and intensity can be affected by changes in the location of the

device with respect to the radiation source and the presence of radiation absorption and scattering materials.