Comments on "Comparison of the neutron radiation tolerance of bipolar and junction field effect transistors"

In the above letter, Buchanan, Dolan, and Roosild have compared bipolar and field effect transistors based on a lifetime damage constant of 2.4 × 10⁵nsċcm^-2. This constant is applicable only at very low injection levels and is, therefore, not appropriate for bipolar transistors; a value of 2 × 10⁶nsċcm^-2is applicable to bipolar transistors in normal operating current ranges (injection level ≈1.0). The conclusion that field effect devices are inherently harder by a factor of five to ten is, therefore, not justified. Application of their comparison criteria using the appropriate damage constant leads to the conclusion that junction and field effect transistors are comparably hard.