Thin film membranes
Application in X-ray, EUV technology and electron beam based systems
Following Moore’s law, semiconductor technology continues to demand for ever smaller feature sizes. This requires more and more innovative and specific key components, like thin film membranes and windows. The common field of application of these membranes is systems employing high energy beams, like in in x-ray, EUV or electron beam based systems. Thin film membranes are used to improve the spectral content or spatial distribution of such beams or to provide a transparent gas or particle barrier between different parts of a system.
Typical membrane or window thicknesses range from 10nm to 10’s of µm thick, employing materials such as Silicon, Silicon Nitride, metal silicides, metals and Carbon/graphene. Stress engineering and clean operation is of the highest importance. Materials and thicknesses are chosen to best fit customer and application requirements. A wide range of measurement equipment to measure stack layer thicknesses, defectivity and membrane ruggedness enables the highest level of process control.
Process development and manufacturing experience
For over ten years, Philips Innovation Services MEMS Foundry has been active in process development and manufacturing of ultra-thin film membranes and windows for a large variety of applications. Working with leading companies in the field, important steps have been made in membrane technology. Like 40nm ultra-thin polysilicon-based membranes that have been developed and manufactured for EUV applications; featuring transmission rates in the range 80-90% and sizes over 100cm2. These membranes are multi-layer structures with precisely engineered stress levels.
A wide variety of functionalities can be added to a membrane such as:
- anti-reflection coatings
- anti-oxidation coatings
- mirror coatings
- blocking layers for specific wavelengths
- bio-compatible coatings.
Our experienced experts can help you to select and develop the best membrane stack configuration to suit your product requirements.
What are thin film membranes?
Thin film membranes, or windows, are ultra-thin freestanding structures within a robust frame, typically made from silicon wafers. These membranes or windows provide spacial or spectral filtering functions for high-energy beams used in semiconductor processing or material analysis. Often they also function as gas or particle barriers. Examples are windows used in Transmission Electron Microscopy (TEM) or in X-ray Diffraction (XRD) instruments. Other application examples are in EUV semiconductor equipment.
Robbert van der Waal
Business Development Director
Our state-of-the-art tools allow us to add a wide variety of features to the membranes.
Unique features of our thin film membranes:
- Large variety in membrane sizes up to 150cm2
- Ultra-thin membranes (5-100nm); thicker (in the µm range) is possible
- Various materials: Si, SiN, C, metal silicides, oxides, metals
- High transmission rates
- Added functionalities by adding nanometer to micrometer thin layers on one or both sides of the membrane (e.g. IR blocking layers, capping layers)
- Added functionalities by structures on or in membranes (e.g. gratings)
- Various membrane geometries (e.g. square, rectangle, circular)
- Tuned pre-stress
What thin film membranes look like
Thickness and material variations
A collection of membranes of 1 cm2 size and a thickness of a few nanometer. The various colors are caused by variations in thickness and material.
- Top left: 5 cm2, 50nm thin membrane with a reinforced grating on top.
- Top right: 640 µm2 SEM image of the reinforced grating.
- Bottom left: 130mm circular honeycomb grid membrane.
- Bottom right: 20 µm2 SEM image of the honeycomb grid membrane.
Membrane part of static bio-containers for cell culture monitoring. The 8 µm thick membrane is based on a combination of SiN and SiO2
Interested in how we can make your next thin film membrane?
Learn more about our MEMS & Micro Devices services
The complexity of MEMS can be seen by the extensive range of different markets and applications. For instance, MEMS can be found in systems ranging across automotive, medical, electronics, communication, semi-conductor, defense, aerospace, and more.
Are you contemplating the use of MEMS devices in your system in order to create a sustainable competitive advantage? When your current solution just doesn’t seem to do the trick, a custom MEMS might be worthwhile investigating. How feasible would a custom MEMS be for you?