Table 7: Typical atomic concentrations of trace elements from combined PIXE/RBS analysis with 1.2 MeV protons (all values given in ppm) of two large-area 32.8 mm diameter ZnO thin films on sapphire. The PLD target was sintered from 99.9995 at.% ZnO powder. Films were grown with stainless steel substrate holder at growth temperature of about 650°C. Therefore, the Fe concentration is much higher at the wafer edges. Most elements are below the detection limits.

Sample*SiKCaTiVCrMnFeNiCu

E391 c1,342<1624<11<14<152035<67<153
E391 e<9013028<13<1628<191,069<69<166
E392 c<971<30<24<21<2450<26<33<104<215
E392 e<1,272545127<298541206<103<243

*Sample no. E391 and E392, c and e stand for center and edge analysis position on the wafer, respectively.