Among several methods to grow the ZnO film

the DC sputtering (DCS) by using sil icon or silicate substrate appears easier in growth and with lower cost. However

the later needs high temperature (800～1000℃) treatment in order to obtain the film with a qualified orientation. It is then the motivation in our research to study the annealing effect on the structure and the luminescent characterization of the ZnO films. In our previous work

the X-ray diffraction with glancing input angle (GXRD) was measured on as-grown and annealed samples

which indicated a triangular compound zinc silicate appeared while the temperature higher then 800℃. In this work

the cathodoluminescence (CL) spectra of a ZnO film on Si

a nnealed at different temperature

were measured. The results showed that

the crystal quality of the film improved with increasing the annealing temperature

while the hexagonal phase of the ZnO film transformed into a kind of mixture phase including a hexagonal and a trigonal phase

after annealing at the temperature lower then 800℃ for one hour. The CL spectrum also shows the intrinsic emission bands of ZnO (two emission bands at 390nm UV band and 505nm green band) and Zn

2

SiO

4

(just one emission band at 525nm)

in which the ZnO is the main source of the spectrum (this is indicated by the red shift of the green band from 505nm to the 525nm band

and the width of the green band was narrowed

as increasing the annealing temperature). Increasing the temperature continuously up to 950℃ changed the main source of sample’s luminescence from the emission of ZnO to the emission of zinc silicate (the red shift stopped at the 525nm). This indicates acreation of new ternary compound Zn

2

SiO

4

in the film. In conclusion

in order to obtain a qualified crystalline ZnO films on silicon or silicate glass grown by DCS method

it is necessary to use heat treatment with high temperature. Although the crystalinity of the film was improved along with increasing the annealing temperature

however

a new ternary compound Zn

2

SiO

4

with triangular structure was found in the films annealed at the temperature higher than 770℃. Therefore

we have to face to such perplex if we decide to choose the DCS or other methods which needs a high temperature treatment to grow ZnO film on silicon

although such methods may have fairly simple techniques and are cheap in cost.