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| Questions & Answers |
We appreciate you registering for our webinar Ion Beam Etch Solutions to Drive Next Generation MEMS and Sensor Performance held on October 6th in conjunction with Yole Development. Veeco has compelling technology that addresses many challenges faced by the MEMS and magnetic sensor industries. Below you will find answers to questions that we did not have time to respond to during the webinar. We hope you find this informative and invite you to email if you have additional questions.
Q. What are some strategies to eliminate re-deposition on the sidewalls?
A. There are multiple process steps that can be applied to minimize/eliminate re-deposition. The typical method is to utilize a multi-step process where more direct angles are used for etching the feature and then shallow angles are used to clean the sidewalls of re-deposition.
| Ar ions, at near normal incidence |
Ar ions, glancing incidence |
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| Remove redeposition through use of multiple angle ion beam etching. |
Q. What is the difference between Ion Milling (like TEM sample preparation) and Ion Beam Etch?
A. These are two separate technologies. TEM uses focused e-beam source (using a filament for plasma generation) with different energetics; it could not be used to etch a full wafer. The Veeco IBE uses a broad beam RF-ICP (filamentless) ion source with collimated grid optics designed to etch up to 200mm diameter substrates. The combination of source design and optics allows for excellent CD control across wafer along with additional knobs for controlling sidewall angle, etch rate, redeposition, surface roughness, magnetic damage, etc.
Q. Are there material limitations for Ion Beam Etching?
A. Ion Beam Etching is physical etch so there are no limitation in the materials that can be etched. It is not dependant on the identification of the proper chemistry to interact with the materials being etched. This lends itself to certain process steps or applications were the ideal chemistry is not available or hard to optimize (damage concerns or optimization time) or when there is a requirement to etch multiple layers of dissimilar materials in a single process step.
Q. What are the advantages of the ability to tune the ion source?
A. Key areas were this has been proven to be advantages are:
• Control of plasma density across the ion source improves uniformity profile across the wafer at all incident angles
• Allows for compensation of non-uniform upstream steps (adjusting for incoming concave or convex profiles)
Q. What controls the etch rate and selectivity in Ion Beam Etching?
A. Combinations of extraction voltage, current and beam angle will define the sputter rate for a given material. Some materials behave differently as incidence angle is changed thus changing the selectivity or relative etch rate ratios. The chart shows how the etch rate varies with angle for non-reactive etch:
Further selectivity, can be controlled with the addition of reactive gas component. Depending on materials, combination of non-reactive and reactive species will either enhance or reduce sputter yield and can be optimized to meet the desired outcome (rate, selectivity, etc). |
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| Veeco Instruments Inc. creates world-class ion beam sources and ion beam process equipment solutions for manufacturers using thin film etch and deposition technology to create components such as: lasers, precision optics, LED devices (high-brightness light emitting diodes), thin film magnetic heads (TFMH) for hard drives and other emerging technologies. |
| Veeco Instruments Inc. | Terminal Drive | Plainveiw, NY 11803 |
| Phone: 516.349.8300 | Fax: 516.349.8321 | Email: vce-support@veeco.com |
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