ABSTRACT
As introduced in Chapter 3 and explained in detail in Chapter 5, soft errors can be caused in part by energetic alpha particles (<10 MeV), emitted from ultratraces of radioactive contaminants in circuit materials, that can penetrate transistor junctions of semiconductor devices. As device dimensions have decreased and circuit complexity has grown, the probability of alpha-induced soft error has mechanically increased, justifying the efforts of the microelectronics industry to select and use lower-alpha-emitting materials at both wafer and packaging levels. Ultralow-background alpha-particle counting has become an important issue for the semiconductor industry, a domain for which alpha-emissivity levels (i.e., the rates of emission of alpha radiation measured in counts per unit area and per unit time) are typically several orders of magnitude lower than for other disciplinary fields, such as geology.
