1 / 10

MEMS Two-Phase Vapor Escape Heat Exchanger

MEMS Two-Phase Vapor Escape Heat Exchanger. Milnes David Tarun Khurana Christopher Anderson. Process Flow. Diffusion Clean Oxide Growth Al. Sputter Backside Pattern (heaters & sensors) Al Etch Ashing PRX 1000 Clean Backside LTO deposition Backside protect Front-side Oxide Etch (HF)

zander
Télécharger la présentation

MEMS Two-Phase Vapor Escape Heat Exchanger

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. MEMS Two-Phase Vapor Escape Heat Exchanger Milnes David Tarun Khurana Christopher Anderson

  2. Process Flow • Diffusion Clean • Oxide Growth • Al. Sputter • Backside Pattern (heaters & sensors) • Al Etch • Ashing • PRX 1000 Clean • Backside LTO deposition • Backside protect • Front-side Oxide Etch (HF) • Front-side pattern (channels) • Front-side channel etch (STSDRIE) • Backside pattern (bond pads) • Pad etch

  3. Process Layout • Backside pattern (through etch) • Through etch (STS DRIE) • Final released device • Adhesive coat on transfer substrate • Contact printing of adhesive • Membrane attachment via UV curing • Attachment of patterned double sticky tape (vapor channel) • Top cover integration

  4. Images of the Heaters and Sensor open bond pads

  5. Typical Defects • Shorts (bridging) • Voids • Scratches – due to handling errors, motivates thicker LTO deposition (5000 A)

  6. Resistance Measurements 4.4 250 ? 150 401 385 506 400 43 389 44 ? 42 383 43 381 410 393 397 380 423 367 5.0 Ground lines = 4.7 ± 0.4  Sensors = 392 ± 15  Heaters = 43 ± 0.8  In all cases resistance is almost twice as high as predicted.

  7. LTO300 Deposition Average dep rate: alternate arrangement = 58 A/min Consecutive arrangement = 40 A/min Average etch rate pad-etch rate: LTO oxide = 3540 A/min Thermal oxide = 400-600 A/min

  8. STS issues • STS down for a month, expected to be up by 1st week of Aug. • Alternatives Pursued: • Getting trained on STS2 (through-etch still not possible) • Outside DRIE and machining service vendors • American precision dicing (can do through etch features) • Laserod laser machining (~ $200 per wafer) • ISSYS • Honeywell MEMS foundry • IMT • Investigated UC-Berkeley and UCSB fab • Training and qualification time is an issue (about a week in each case) • Investigating wet etch options (KOH or TMAH) • Requires oxide or nitride as mask • Significant undercutting can result in much larger features • Changing process flow to perform pad etch first to save time. • Created back-up device in Copper.

  9. Design of Copper Device

  10. Thanks! Questions?

More Related