Film deposition assisted by angular selective etch on a surface

An ion etch assisted deposition apparatus deposits a thin film upon a substrate having a three dimensional feature, using an ion etching source and deposition source arranged at similar angles relative to the substrate and at an angle α relative to each other. The angle α is selected to be substantially equal the supplement of the angle α′ formed between the three dimensional feature on the substrate and the substrate surface. In this configuration the relative flux of energetic etch ions and deposition atoms is adjusted to prevent the growth of poor quality deposited material.