Obliquely vapor deposited thin film (OVD-TF) is characterized by its unique inclined columnar structure (ICS). In previous work, the form birefringence originated from ICS was utilized to form amorphous Ta2O5 thin film retardation plates (TF-RPs). By reducing the size of ICS in nm scale range, the film was durable and transparent getting rid of the haze inherent in usual OVD-TF. In the present work, again TF-RPs were formed on fused silica substrates but this time by simultaneous oblique deposition from two Ta2O5 sputtering sources located at opposite azimuthal directions in a specially designed sputter-deposition apparatus. A typical birefringence obtained was (Delta) n equals 0.087, 0.049 and 0.043 at the wavelength of 300 nm, 500 nm and 800 nm, respectively. A film of 2550 nm thick can make a quarter wave plate at 500 nm. The columnar structure which inclined no more this time does not cause birefringence for a normally incident light. The birefringence comes this time from the fact that the columns are less closely spaced in the plane of the vapor incidence (PVI) than normal to PVI. This is the first example that the birefringence of this type is utilized to fabricate TF-RPs. The growth mechanism of this anisotropic nm scale structure was discussed with 3D-simulation of ballistic deposition.