Fast photoconductive materials for wideband A/D conversion and monolithic integration with CMOS
Abstract/Contents
- Abstract
- All-electronic analog-to-digital converter (ADC) performance is limited by low input bandwidth and high aperture uncertainty. To benefit from the bandwidth and timing accuracy advantages of photonic devices, we investigated a photoconductive-sampling-based photonic A/D conversion system utilizing low-temperature-grown GaAs (LT-GaAs) metal-semiconductor-metal (MSM) photoconductive switches which were flip-chip-bonded with silicon-CMOS ADCs and demonstrated a two-channel prototype system with ~ 3.5 effective-number-of-bits of resolution over an input bandwidth up to 40 GHz and an estimated sampling jitter of less than 80 fs. We studied three material systems targeting the high-speed photoconductive switch application. First, for LT-GaAs films grown on GaAs substrates, we significantly improved the MSM switch performance by systematic optimization of LT-film growth and annealing conditions according to design-of-experiments (DOE) principles. The full-width at half-maximum switching window characterized by electro-optic sampling is ~ 2 ps. To enable monolithic integration of GaAs devices with finished Si IC chips, we studied low temperature growth of GaAs films, both on Si substrates and on SiO2 films. All the experiments, including film growth, annealing and device processing, were performed at temperatures safe for completed IC chips with final metallization and passivation layers. Testing results showed that the switch performance was comparable to or exceeded the reference LT-GaAs switches made on GaAs wafers which were used to fabricate the prototype ADC system. As a final proof of concept, we successfully integrated polycrystalline GaAs switches monolithically on a completely fabricated CMOS amplifier and achieved a functional optical receiver without modifying the underlying Si circuit performance. The beauty of this approach is its simplicity, minimum fabrication disturbance and greater applicability into other areas. We believe this to be the first successful demonstration of monolithic integration of GaAs devices on a fully completed Si chip, and most importantly, demonstrating fully functional and un-degraded performance.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Copyright date | 2010 |
| Publication date | 2009, c2010; 2009 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Ma, Kai, active 2009 |
|---|---|
| Associated with | Stanford University, Department of Materials Science and Engineering |
| Primary advisor | Harris, J. S. (James Stewart), 1942- |
| Thesis advisor | Harris, J. S. (James Stewart), 1942- |
| Thesis advisor | Miller, D. A. B |
| Thesis advisor | Nix, William D |
| Advisor | Miller, D. A. B |
| Advisor | Nix, William D |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Kai Ma. |
|---|---|
| Note | Submitted to the Department of Materials Science and Engineering. |
| Thesis | Ph.D. Stanford University 2010 |
| Location | electronic resource |
Access conditions
- Copyright
- © 2010 by Kai Ma
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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