Adjustment of N and K values in a darc film

A process for forming a dielectric anti-reflection coating, having a predetermined refractive index, extinction coefficient and final thickness, comprising:

• through simulation, determining composition, thickness, and surface treatment for each of a number of layers of said dielectric whereby said number of layers have a total thickness equal to said final thickness and a structure formed of said number of layers has said predetermined refractive index and extinction coefficient;
• then
• (a) depositing a layer of dielectric material having the thickness and composition determined through said simulation;
• (b) exposing said layer of dielectric material to the surface treatment determined through said simulation;
• and
• repeating steps (a) and (b), with no intervening layers, until said number of layers has been deposited.

A process for forming a dielectric anti-reflection coating, having a predetermined refractive index, extinction coefficient and final thickness, comprising the steps of:

• (a) depositing a dielectric layer having a thickness that is at most half said final thickness;
• (b) exposing said dielectric layer to a gaseous plasma for a period of time;
• repeating steps (a) and (b), with no intervening layers, thereby forming a stack of layers, until a total layer thickness equal to said final thickness has been achieved;
• after each stack has been formed, determining refractive index and extinction coefficient values for that stack;
• and
• based on said determined values, adjusting conditions during subsequent steps whereby, after said final thickness has been achieved, a final stack having said pre-determined refractive index and extinction coefficient is formed.