Self-Aligned Angled Optical Device Structures via Selective Etching
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Solution Overview
Problem
Current methods for forming optical device structures, such as those used in augmented and virtual reality, are time-consuming and costly due to complex patterning processes.
Innovation Solution
A method involving the use of a hardmask layer on a mandrel material, patterning, and angled etching to form angled mandrels and optical device structures, allowing for the deposition and removal of device material at specific angles to create efficient optical device structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional patterning processes are used to form optical device structures, then manufacturing precision can be achieved, but the process becomes time-consuming and costly
Solution Approach 1:
The method performs preliminary patterning of a hardmask layer to define mandrel regions before forming the final optical device structures. This preliminary action creates a template that guides subsequent self-aligned formation, eliminating the need for multiple complex patterning steps and reducing overall formation time while maintaining precision
Solution Approach 2:
The optical device structures are formed in a self-aligned manner where the structures automatically position themselves relative to the mandrels during the formation process. This self-service mechanism eliminates the need for additional alignment and patterning operations, significantly reducing process time and cost while ensuring precise structural formation
2Manufacturing precision
If conventional patterning processes are used to form optical device structures, then manufacturing precision can be achieved, but the process complexity increases
Solution Approach 1:
The hardmask layer is patterned in advance to create mandrel definitions that serve as templates for the optical device structures. This preliminary patterning simplifies the overall process by consolidating multiple alignment steps into a single initial patterning operation, reducing process complexity while maintaining precision
Solution Approach 2:
The self-aligned formation process allows structures to automatically position themselves relative to the mandrels during formation. This self-service mechanism eliminates complex alignment procedures and multiple patterning steps, significantly reducing process complexity while ensuring precise structural formation
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method reduces the complexity and cost of forming optical device structures while achieving precise angled structures with sub-micron dimensions, improving the efficiency and optical properties of augmented and virtual reality devices.
Implementation Method 1
etching the exposed portions of the mandrel material at a first etch angle to form a plurality of angled mandrels
Implementation Method 2
depositing a device material on the substrate and on a mandrel upper surface, a leading sidewall, and a trailing sidewall
Implementation Method 3
removing the device material disposed on the substrate and the mandrel upper surface with an angled etch process at a second etch angle
Data Source
AI summary
Embodiments described herein provide for methods of forming angled optical device structures. The methods described herein utilize etching a mandrel material with an etch chemistry that is selective to the hardmask, i.e., the mandrel material is etched at a higher rate than the hardmask. Therefore, mandrel trenches are formed in the mandrel material. Device material of the angled optical device structures to be formed is deposited on the plurality of angled mandrels. An angled etch process is performed on portions of the device material such that the angled optical device structures are formed.