The effect of nitrogen on the growth of ZnO thin film has been investigated as follows: N radical treatment on the surface and thin film deposition. ZnO surface after N radical exposure was studied for optimizing the growth conditions of N-doped ZnO thin film. These studies indicate that the increase of substrate temperature leads to the decrease in the amount of N, and substrate temperature of 150 degreesC shows the maximum amount of N on ZnO surface. The ZnO thin films deposited at 150 and 300 degreesC were found to have the nitrogen contents of 1.2 x 10(19) and 8.6 x 10(18) atoms/cm(3). Above results suggest that the surface reaction is a key process of N doping in ZnO by chemical vapor deposition (CVD). (C) 2002 Elsevier Science B.V. All lights reserved.