Significance and Use
Electronic circuits used in space, military, and nuclear power systems may be exposed to various levels of ionizing radiation. It is essential for the design and fabrication of such circuits that test methods be available that can determine the vulnerability or hardness (measure of nonvulnerability) of components to be used in such systems.
Some manufacturers currently are selling semiconductor parts with guaranteed hardness ratings. Use of this guide provides a basis for standardized qualification and acceptance testing.
Scope
1.1 This guide presents background and guidelines for establishing an appropriate sequence of tests and data analysis procedures for determining the ionizing radiation (total dose) hardness of microelectronic devices for dose rates below 300 rd(SiO
1.2 The methods and guidelines presented will be applicable to characterization, qualification, and lot acceptance of silicon-based MOS and bipolar discrete devices and integrated circuits. They will be appropriate for treatment of the effects of electron and photon irradiation.
1.3 This guide provides a framework for choosing a test sequence based on general characteristics of the parts to be tested and the radiation hardness requirements or goals for these parts.
1.4 This guide provides for tradeoffs between minimizing the conservative nature of the testing method and minimizing the required testing effort.
1.5 Determination of an effective and economical hardness test typically will require several kinds of decisions. A partial enumeration of the decisions that typically must be made is as follows:
1.5.1 Determination of the Need to Perform Device CharacterizationFor some cases it may be more appropriate to adopt some kind of worst case testing scheme that does not require device characterization. For other cases it may be most effective to determine the effect of dose-rate on the radiation sensitivity of a device. As necessary, the appropriate level of detail of such a characterization also must be determined.
1.5.2 Determination of an Effective Strategy for Minimizing the Effects of Irradiation Dose Rate on the Test ResultThe results of radiation testing on some types of devices are relatively insensitive to the dose rate of the radiation applied in the test. In contrast, many MOS devices and some bipolar devices have a significant sensitivity to dose rate. Several different strategies for managing the dose rate sensitivity of test results will be discussed.
1.5.3 Choice of an Effective Test MethodologyThe selection of effective test methodologies will be discussed.
1.6 Low Dose RequirementsHardness testing of MOS and bipolar microelectronic devices for the purpose of qualification or lot acceptance is not necessary when the required hardness is 100 rd(SiO
1.7 SourcesThis guide will cover effects due to device testing using irradiation from photon sources, such as 60Co irradiators, 137Cs irradiators, and low energy (approximately 10 keV) X-ray sources. Other sources of test radiation such as linacs, Van de Graaff sources, Dymnamitrons, SEMs, and flash X-ray sources occasionally are used but are outside the scope of this guide.
1.8 Displacement damage effects are outside the scope of this guide, as well.
1.9 The values stated in SI units are to be regarded as the standard.
