We have developed a repeatable LPCVD process of forming small-size and high-density silicon quantum dots by investigating the effect of substrate type, chemical treatment, deposition temperature, and deposition time and have fabricated EEPROM which showed room temperature Coulomb blockade effect for the first time. Also, we observed that the surface of $Si_3N_4$ is suitable for uniform quantum dots with high density and small dimension. To take advantage of nitride film while keeping the high interface quality between the tunneling dielectrics and Si substrate, oxide-nitride tunneling dielectrics is proposed in this paper. This proves the feasibility of practical silicon quantum dot memory with oxide-nitride tunneling dielectric.