Glancing angle deposition of thin films
AssigneesThe Governors of the University of Alberta, Alberta Microelectronic Corporation
InventorsKevin J. Robbie, Michael J. Brett
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Abstract
A method of making vapor deposited thin films by rotating a substrate in the presence of an obliquely incident vapor flux. The substrate is rotated about an axis normal to the surface of the substrate while depositing a vapor flux, and then paused while depositing vapor flux to cause columns of a thin film to grow obliquely. The resulting thin film exhibits a porosity that is not dependent on the column angle of the resulting thin films.
Claims18
A method of growing vapor deposited thin films, the method comprising the steps of:
- A) initially exposing a surface of a substrate to a vapor flux under a given set of growth conditions at an oblique incident angle while rotating the direction of arrival of the vapor flux at the substrate at a rotation speed about a normal to the substrate to grow a first portion of a thin film formed of a plurality of columns growing in a first growth direction;
- B) subsequently, and while exposing the surface to vapor flux, altering the set of growth conditions to cause a second portion of each of the plurality of columns to grow in a growth direction offset from the first growth direction;
- and
- C) repeating steps A and B to create a first thin film formed of columns on the substrate.
A method of growing vapor deposited thin films, the method comprising the steps of:
- exposing a surface of a substrate to a vapor flux at an oblique incident angle greater than 70° while rotating the direction of arrival of the vapor flux at the substrate at a rotation speed about a normal to the substrate to grow a thin film formed of a plurality of columns growing in a first growth direction;
- and
- the rotation speed being sufficiently high that the direction of arrival of the vapor flux at the substrate rotates at least once within the time required for the thin film to grow a distance, measured normal to the substrate, substantially equal to the adatom diffusion length of the material being deposited.
A method of filtering electromagnetic radiation, wherein the electromagnetic radiation includes radiation having a frequency λ and the electromagnetic radiation is propagating along a light path, the method comprising the steps of:
- placing an optical filter in the light path, wherein the optical filter comprises plural helical columns extending from a substrate, the helical columns each having a pitch p sufficiently smaller than λ that propagation of light is unaffected by the helical structure of the columns.
Dependencies are inferred from the claim text.