MEMS Sensor Infrared Protection via Surface Patterning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
MEMS sensors are vulnerable to non-invasive infrared investigations, which compromise the security of hardware-based keys by allowing partial reading or copying through the transparent silicon material, reducing data security.
Innovation Solution
A surface area of the MEMS unit or sensor is patterned to absorb, reflect, or diffusely scatter at least 50% of incident infrared light, making it difficult for infrared spectroscopic investigations to access internal physical properties, using methods like KOH etching or surface patterning to create a non-transparent surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the silicon material is kept transparent for infrared light to maintain the structural integrity of the MEMS sensor, then the sensor can be manufactured with standard materials and processes, but infrared investigations can read out key information through the transparent material
Solution Approach 1:
The patent applies infrared-reflecting or infrared-absorbing coatings to the surface of the MEMS sensor that are transparent to visible light but block infrared light. This allows the sensor to maintain its structural transparency for optical sensing while preventing infrared spectroscopic investigations from reading out key information through the material.
Solution Approach 2:
The patent introduces an intermediate layer (infrared-reflecting or infrared-absorbing coating) between the infrared light and the silicon material. This intermediary layer blocks infrared light from penetrating through the transparent silicon, thereby preventing non-invasive reading of key information while maintaining the structural integrity of the sensor.
2Reliability
If infrared-reflecting or infrared-absorbing coatings are applied to block infrared light, then security against infrared investigations is improved, but the manufacturing process becomes more complex
Solution Approach 1:
The patent utilizes materials or coatings with specific optical parameters that are transparent to visible light wavelengths but opaque to infrared wavelengths. By selecting materials with appropriate optical parameters (transmission characteristics), the patent achieves security enhancement without requiring complex multi-layer structures or intricate manufacturing processes.
3Reliability
If the surface is patterned to absorb or reflect infrared light, then infrared transmission is reduced and security is enhanced, but the surface roughness increases which may affect optical performance
Solution Approach 1:
The patent applies smooth infrared-reflecting or infrared-absorbing coatings that provide optical blocking functionality without creating surface roughness. These coatings maintain a smooth surface profile that does not interfere with the optical performance of the MEMS sensor while effectively blocking infrared light.
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
The solution significantly enhances the security of MEMS sensors by preventing or rendering difficult non-invasive infrared investigations, ensuring the integrity of the keys derived from physical properties, while making invasive attempts laborious and potentially damaging.
Implementation Method 1
at least one area of a surface of the MEMS unit or of the MEMS sensor is patterned in such a way that, due to its optical properties, this patterned area absorbs, reflects or diffusely scatters at least 50%, in particular at least 90% of an incident infrared light
Implementation Method 2
at least one area of a surface of the MEMS unit or of the MEMS sensor is patterned in such a way that, due to its optical properties, this patterned area absorbs, reflects or diffusely scatters at least 50%, in particular at least 90% of an incident infrared light
Implementation Method 3
at least one area of a surface of the MEMS unit or of the MEMS sensor is patterned in such a way that, due to its optical properties, this patterned area absorbs, reflects or diffusely scatters at least 50%, in particular at least 90% of an incident infrared light
Data Source
AI summary
A method is provided for protecting a MEMS unit, in particular a MEMS sensor, against infrared investigations, a surface patterning being performed for at least one first area of a surface of the MEMS unit, the first area absorbing, reflecting or diffusely scattering more than 50%, in particular more than 90% of an infrared light incident upon it.