In this paper, we present thin-film photodetector (TFPD) image sensors for the short-wave infrared (SWIR) range. Monolithic integration of quantum dot (QD) absorbers enables quantum efficiency of 70% at 1400 nm and pixel pitch below 2 μm. We present image sensors on custom CMOS readout fabricated using 130 nm node. We review latest advancements on the photodiode stack and the pixel engine, including the thin-film pinned photodiode architecture. Furthermore, we study the manufacturing flows to realize full wafer capability for volume processing. QD image sensors are paving the way to add augmented vision into future XR systems with extra functionalities.
CMOS image sensors for visible wavelength range have been receiving much attention over the last two decades, offering ultra-low power and camera-on-chip integration. Imagers are now able to extract additional information from the scene thanks to infrared sensing for recognition or Time-of-Flight for 3D imaging. Such capabilities enable an unlimited amount of applications in several businesses, i.e. automotive, industrial, life science, security, agricultural or consumer. Imec has been continuously developing advanced technologies together with innovative pixel and circuit architectures to realize prototypes for various scientific applications. Thanks to state-of-the-art IIIV and thin-film (organics or quantum dots) material integration experience combined with imager design and manufacturing, imec is proposing a set of research activities which ambition is to innovate in the field of low cost and high resolution NIR/SWIR uncooled sensors as well as 3D sensing in NIR with Silicon-based Time-of-Flight pixels. This work will present the recent integration achievements with demonstration examples as well as development prospects in this research framework.
Voids in copper lines are a common failure mechanism in the back end of line (BEOL) of integrated circuits manufacturing, affecting chip yield and reliability. As subsequent process nodes continue to shrink metal line dimensions, monitoring and control of these voids gain more and more importance [1]. Currently, there is no quantitative in-line metrology technique that allows voids to be identified and measured. This work aims to develop a new method to do so, by combining scatterometry (also referred to as Optical Critical Dimension or Optical CD) and low-energy x-ray fluorescence (LE-XRF), as well as machine learning techniques. By combining the inputs from these tools in the form of hybrid metrology, as well as with the incorporation of machine learning methods, we create a new metric, referred to as Vxo, to characterize the quantity of void. Additionally, the results are compared with inline electrical test data, as higher amounts of voids were expected to increase the measured resistivity. This was not found to be the case, as the impact of the voids was much less of a factor than variation in the cross-sectional area of the lines.
Erbium doped polymer waveguide amplifier for operation at 1.55 micrometers was studied. A fluorinated polyimide was doped with Er ions using ion implantation. The samples were irradiated at room temperature by 320 keV Er2+ and 160 keV Er+ ions. Doses used were 1 by 1015/cm2 and 1 by 1014/cm2 respectively. The implanted samples were characterized using Rutherford Backscattering and SIMS analysis. The implanted ion profile was nearly Gaussian with range of 0.25 micrometers for the 320 keV implant and 0.12 micrometers for the 160 keV implant. A Gaussian implanted ion profile, matched with the electric field profile of the waveguide mode, can enhance the efficiency of energy transfer between the waveguide mode and the active ions. The implant depth of Er in polyimide at the energies used is shallow. In order to achieve the overlap with the electric field profile, a two layer waveguide amplifier structure is proposed. Such doping and waveguide fabrication techniques are compatible with the existing silicon technology.
We report the fabrication and processing of thin film MSM silicon photo-detector and thin film VCSEL for optoelectronic interconnects. These two components, together with polyimide wave-guide can be used in constructing the high sped, low power, low cost optical interconnection system. Such a system will provide the fast board level data transmission. The DC and AC characteristics of thin film silicon MSM photo-detector, and the I-V and L-I characteristics of thin film VCSEL are measured.
Neodymium (Nd) doped polymer based optical amplifiers have been studied. NdCl3.6H2O and Nd(III) hexafluoracetylacetonate were used as dopants. Photoluminescence at 0.89 micrometers , 1.06 micrometers and 1.33 micrometers from Nd ions in polyimide was detected. Phase separation with possible formation of liquid crystal polymer was observed in NdCl3.6H2O doped polyimide. Thin film waveguides and multimode channel waveguides were fabricated using a novel planarizing technique to reduce scattering losses. Optical gain of about 5.4 dB at 1.06 micrometers was demonstrated in a 5 cm long NdCl3.6H2O doped polyimide channel waveguide.
A multifunctional polymeric deice capable of performing functions such as electro-optic modulation, optical amplification, and electro-optic switching simultaneously is described. All three modules can be built on a single substrate. A novel polymeric modulator with structure based on 1 X 2 Y-fed directional coupler is demonstrated. The results of preliminary investigations on optical amplifiers are presented.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.