Localized Substrate Heating for Precise Grating Etch Depth

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Solution Overview

Problem

Manufacturing waveguides on substrates is challenging due to uncontrolled temperature across the substrate, leading to inconsistent depth profiles of gratings, which affects the augmented reality experience.

Innovation Solution

A method involving individually controlling heating pixels and light emitting diodes (LEDs) in a substrate support assembly to provide temperature distributions on a substrate, allowing for localized heating and precise control of grating depths when exposed to an ion beam, enabling different temperature zones for forming fins with varying depths on the gratings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If conventional heating methods are used, then the substrate can be heated, but the temperature distribution across the substrate becomes uncontrolled, leading to inconsistent grating depth profiles

Engineering Contradiction:
Improvesubstrate temperature controlVSAvoidgrating depth profile consistency
Core Design Contradiction:
TemperatureVSManufacturing precision

Solution Approach 1:

The heating system is divided into multiple independently controllable heating zones or heating elements across the substrate surface. Each heating zone can be controlled separately to achieve the desired temperature distribution profile, allowing different regions of the substrate to have different temperatures during the grating formation process.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the substrate are subjected to different temperature conditions during grating formation. By locally controlling the temperature in each heating zone, the etch depth and grating profile can be precisely controlled in different areas, enabling consistent depth profiles across the entire substrate.

Inventive Principle:
Principle #3Local quality

2Ease of manufacture

If uniform temperature is applied across the substrate, then the heating process is simple, but the etch depth varies across different regions due to temperature gradients

Engineering Contradiction:
Improveheating process simplicityVSAvoidetch depth control
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The heating system transitions from a static uniform temperature approach to a dynamic temperature distribution approach. The heating zones can be independently adjusted during the process to compensate for temperature gradients and achieve uniform etch depth across the substrate, balancing process complexity with manufacturing precision.

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If multiple waveguides with different physical properties are manufactured on the same substrate, then the optical device functionality is improved, but the manufacturing process complexity increases

Engineering Contradiction:
Improveoptical device functionalityVSAvoidmanufacturing process complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Different regions of the substrate are processed at different temperatures to create waveguides with different physical properties. This local temperature control enables the formation of multiple waveguide types on a single substrate without requiring separate processing steps for each waveguide type, thus managing manufacturing complexity while achieving versatile optical device functionality.

Inventive Principle:
Principle #3Local quality

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 approach allows for precise control of etch depth across the substrate, ensuring consistent and controlled grating depth profiles, thereby enhancing the manufacturing process of waveguides for augmented reality applications.

Implementation Method 1

individually controlling a plurality of heating pixels disposed in a dielectric body of a substrate support assembly, the plurality of heating pixels providing temperature distributions on a first surface of the substrate

Methodology Applied
Scientific EffectLocalized heating: Heating

Implementation Method 2

the plurality of heating pixels providing temperature distributions on a first surface of the substrate disposed on a support surface of the dielectric body

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

exposing the substrate to the ion beam to form a plurality of fins on the at least one grating

Methodology Applied
Scientific EffectIon beam etching: Ion Beam

Implementation Method 4

the at least one grating having a distribution of depths corresponding to the temperature distributions

Methodology Applied
Scientific EffectThermal control of etch rate:

Data Source

PatentEP3900027B1Methods for controlling etch depth by localized heating
Publication Date: 2024.05.22 APPLIED MATERIALS INC
  • EP3900027B1 patent drawingFigure 1A~1B
  • EP3900027B1 patent drawingFigure 2A
  • EP3900027B1 patent drawingFigure 2B~2C

AI summary

Embodiments of the present disclosure relate to methods for controlling etch depth by providing localized heating across a substrate. The method for controlling temperatures across the substrate can include individually controlling a plurality of heating pixels disposed in a dielectric body of a substrate support assembly. The plurality of heating pixels provide temperature distributions on a first surface of the substrate disposed on a support surface of the dielectric body. The temperature distributions correspond to a plurality of portions of at least one grating on a second surface of the substrate to be exposed to an ion beam. Additionally, the temperatures can be controlled by individually controlling light emitting diodes (LEDs) of LED arrays. The substrate is exposed to the ion beam to form a plurality of fins on the at least one grating. The at least one grating has a distribution of depths corresponding to the temperature distributions.