Textured Substrate Holder Surface for Low-Noise Optical Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing substrate measurement systems face challenges with unwanted background noise signals due to optical beam reflection from substrate holders, which require intricate systems for noise reduction, and are not ideal for compact integrated modules.
Innovation Solution
The substrate holder is designed with a surface featuring a structural element and porous material element, balancing reflective and scattering effects, and is treated with a passivation layer to reduce reflection and corrosion, using materials like nickel and fluorine compounds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a smooth substrate holder surface is used, then optical beam reflection is strong causing background noise, but adding intricate noise reduction systems increases device complexity
Solution Approach 1:
The substrate holder surface is designed with a porous structure that scatters incident optical beams, preventing strong reflections from reaching the detector. This porous texture inherently reduces background noise signals without requiring additional complex noise reduction components, thus maintaining measurement precision while avoiding increased device complexity
Solution Approach 2:
The surface properties of the substrate holder are modified by changing its physical structure from smooth to porous, altering the optical interaction parameters. This parameter change transforms the surface from a reflective interface to a scattering interface, naturally suppressing background noise and improving measurement accuracy without adding system complexity
2Illumination intensity
If a highly reflective substrate holder surface is used, then optical signal strength is high, but background noise from reflection increases measurement errors
Solution Approach 1:
The substrate holder surface is designed with heterogeneous local properties - the porous structure is distributed across the surface to create localized scattering centers. This local quality modification ensures that optical beams are scattered in multiple directions, reducing the intensity of reflected beams reaching the detector while maintaining overall optical interaction, thus reducing background noise without completely eliminating optical signal
Solution Approach 2:
The porous surface structure converts the harmful effect of strong optical reflection (which causes background noise) into a beneficial scattering effect. By intentionally designing the surface to scatter light rather than reflect it directly, the system transforms the potential harm of strong optical interaction into a useful mechanism for noise reduction, improving measurement accuracy
3Strength
If the substrate holder is made from reactive materials, then mechanical strength is high, but corrosion in vacuum environments reduces reliability
Solution Approach 1:
The substrate holder is constructed as a composite structure combining a strong metallic base material with a corrosion-resistant porous surface layer. This composite design maintains the high mechanical strength of the bulk metal while the porous surface layer provides protection against corrosion in vacuum environments, ensuring both strength and reliability
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 design reduces optical signal reflection and corrosion, improving measurement accuracy and system compactness, enabling efficient and precise film thickness and uniformity monitoring in substrate processing.
Implementation Method 1
The surface has a texture that causes an optical beam incident on the surface to scatter in a direction away from an optical detector to be located above the substrate holder
Implementation Method 2
The substrate holder is treated with a passivation layer to reduce reflection and corrosion
Data Source
AI summary
Embodiments described herein relate to substrate holder systems. An apparatus includes a substrate holder having a surface to receive a substrate. The surface has a texture that causes an optical beam incident on the surface to scatter in at least one direction away from an optical detector to be located above the substrate holder.