The p-type ZnO film is obtained out of thermal diffusion of phosphorus (P) atoms from the low energy, high dose implanted Si substrate through rapid thermal annealing (RTA). Many nonactivated P atoms exist on the surface of the shallow-implanted Si substrate and easily out-diffuse into the ZnO films at lower RTA temperatures. The concentration of the p-type ZnO reached 1.13x10(19) cm(-3). The p-ZnO/n-Si heterojunction was fabricated using the one-step RTA process. This method offers various choices of dopants with low energy, high dose implanting into silicon without considering the restriction of the substrate.