present in interplanetary space, they are modulated by solar activities with an
approximately 11-year cycle near the Earth. Ion flux less than 10 GeV will be
screened and reduced by magnetic shielding and particles from the sun during the
“solar maximum” period. On the other hand, the flux of GCRs will increase during
the “solar minimum” period [4, 5].
1.2 Radiation Effects on Semiconductor Devices
There are two types of interactions involving X-rays, gamma rays, electrons, protons, neutrons and heavy ions with the materials—ionizing energy loss and
non-ionizing energy loss (NIEL). As shown in Table 1, by their characteristics, the
radiation effects on semiconductor devices are classified—total ionizing dose (TID),
displacement damage (DD) and single event effects (SEEs).
This section discusses the SEEs in detail. SEEs are the result of interactions
involving materials with radiation via the ionizing energy loss process. SEEs are
divided into two categories—the so-called “soft” and “hard” errors. Although both
classifications are ambiguous, soft errors are generally non-destructive errors, while
400
300
200
100
0
1850 1860 1870 1880 1890 1900
DATE
SUNSPOT NUMBER
1910
1920 1930 1940 1950
18
17
16
15
13
12
11
10
14
400
300
200
100
0
1950 1960 1970 1980 1990 2000
DATE
SUNSPOT NUMBER
2010
2020 2030 2040 2050
22
23
24
21
20
19
Fig. 3 Monthly averages of the sunspot numbers [6]
An Evaluation of Single Event Effects by Heavy Ion Irradiation on Atom. . .
61