ASTM F 448 : 2018

1.1This test method covers the measurement of steady-state primary photocurrent, I_pp, generated in semiconductor devices when these devices are exposed to ionizing radiation. These procedures are intended for the measurement of photocurrents greater than 10⁻⁹ A·s/Gy(Si or Ge), in cases for which the relaxation time of the device being measured is less than 25 % of the pulse width of the ionizing source. The validity of these procedures for ionizing dose rates as great as 10⁸Gy(Si or Ge)/s has been established. The procedures may be used for measurements at dose rates as great as 10¹⁰Gy(Si or Ge)/s; however, extra care must be taken. Above 10⁸Gy/s, the package response may dominate the device response for any device. Additional precautions are also required when measuring photocurrents of 10⁻⁹ A·s/Gy(Si or Ge) or lower.

1.2Setup, calibration, and test circuit evaluation procedures are also included in this test method.

1.3Because of the variability between device types and in the requirements of different applications, the dose rate range over which any specific test is to be conducted is not given in this test method but must be specified separately.

1.4The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.5This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.6This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.