Lateral PIN Photodiode Research Articles

Concentration‐dependent minority carrier lifetime in an In0.53Ga0.47As interdigitated lateral PIN photodiode model based on spin‐on chemical fabrication methodology

AbstractThe fitted parameters for the analytic function used to specify the doping dependence of minority carrier lifetimes for In0.53Ga0.47As (InGaAs) is described in this paper. This model together with other carrier models was used to develop an interdigitated lateral PIN photodiode utilizing InGaAs as the absorbing layer. We propose the usage of spin‐on chemicals such as spin‐on dopants and spin‐on glass to form the p+ wells, n+ wells and the surface passivation layer of the device hence providing a cheap and easy solution versus the conventional epitaxial growth methodology. The modeled device achieved dark currents of 0.21 nA and capacitance of 2.87 nF at an operating voltage of 5 V. Optical illumination at a wavelength of 1550 nm and power of 10 W/cm2 enabled the device to achieve responsivity of 0.56 A/W and external quantum efficiency of 44%. The −3 dB frequency response of the device was at 8.93 GHz and signal‐to‐noise ratio is 36 dB. The developed device shows close correlation with experimentally developed devices developed using other fabrication methodologies. The results of this work would be useful in the thorough development of InGaAs‐based devices based on spin‐on chemical fabrication methodology using commercial device simulation packages. Copyright © 2010 John Wiley & Sons, Ltd.

Integrated Silicon PIN Photodiodes Using Deep N-Well in a Standard 0.18-$\mu$m CMOS Technology

This paper studies integrated silicon photodiodes (PDs) implemented in standard CMOS technologies. A new PIN PD structure utilizing deep n-well is presented, and compared with conventional vertical and lateral PIN PDs at 850-nm wavelength and different bias conditions. Prototype PDs were fabricated in a 0.18-mum standard CMOS technology, and their DC, impulse and frequency responses were characterized. A 70 times 70 mum <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> PD with the new structure achieved a 3-dB bandwidth of 2.2 GHz in small signal at 5-V bias, whereas conventional lateral and vertical PIN PDs could only operate up to 0.94 GHz and 1.15 GHz, respectively. At 5-V bias, the impulse response of the new PD exhibited a full-width at half-maximum pulsewidth of 127 ps, versus 175 and 150 ps for the conventional lateral and vertical ones, respectively. At 15.5-V bias, the bandwidth of this new PD reached 3.13 GHz, with an impulse response pulsewidth of 102 ps. The responsivity of all prototype PDs was measured at approximately 0.14 A/W up to 10-V bias, which corresponded to a quantum efficiency of 20%. The responsivity of the new PD could be further increased to 0.4 A/W or 58% quantum efficiency, when operating in the avalanche region at 16.2-V bias.

Characterization of quantum efficiency, effective lifetime and mobility in thin film ungated SOI lateral PIN photodiodes

This paper presents an analytical model of the optical sensitivity and dark current of thin film SOI PIN diodes validated by measurements. This allows us to prove the very good adequacy of thin film SOI for UV-sensing (quantum efficiency in excess of 60% without any anti-reflection coating and dark current lower than pA for a total diode area of 50 × 50 μm 2) and to propose a new method for extracting the effective lifetime and electron, and hole mobilities in SOI thin film ungated structures.

Backside-Illuminated Lateral PIN Photodiode for CMOS Image Sensor on SOS Substrate

In this paper, we propose a method to design charge-sensing elements for CMOS image sensor pixels on a silicon-on-sapphire (SOS) substrate. To address the low quantum efficiency problem due to very thin active film used, a backside illuminated lateral PIN photodiode on an SOS substrate is proposed and developed. It has the advantages of higher photo response with a PIN structure and improved optical transmission with a backside illumination through a transparent sapphire substrate. An active pixel sensor (APS) based on the PIN and backside illumination has been implemented in a commercially available SOS CMOS process. Acceptable sensitivity in optical conversion from the APS can be achieved, even with the ultrathin silicon film. The APS is demonstrated to function at 1.2 V, giving a dynamic range of 51 dB.

Evaluation of GaAs photodetectors for detection of soft X-ray pulses from laser-induced plasmas

GaAs-based photodetectors (lateral photoconductors and PIN photodiodes) are investigated with the aim to find good items to register nanosecond soft X-ray pulses generated from laser-induced plasmas. Pulse height spectra using light pulses that imitate X-ray pulses are measured and interpreted. Excitation with α particles were used to evaluate the loss of particle-induced charges in our detectors.

Monolithically integrated silicon n MOS pin photoreceiver

A monolithic Si optical receiver is reported that consists of an Si nMOS preamplifier and a novel, lateral Si pin photodiode. The Si photodiode has a bandwidth of 900 MHz and a responsivity of 0.48 A/W at 870 nm. The optical receiver has demonstrated open-eye operation to 370 Mbit/s with 3 µA of signal photocurrent.

Fabrication of a lateral p-i-n photodiode in a Si/(Si0.8Ge0.2/Si) superlattice/Si/sapphire structure

We have fabricated the first silicon on insulator (SOI)-type lateral pin photodiode in a Si0.8Ge0.2/Si superlattice layer grown by molecular-beam epitaxy on a sapphire substrate. The superlattice structure is maintained even after processing at a maximum temperature of 850 °C, and the lateral pin photodiode fabricated in the Si0.8Ge0.2/Si superlattice layer generated about five times as much photocurrent in the 400–1000-nm wavelength range as that in a lateral pin photodiode fabricated in a Si layer of the same film thickness. It is therefore concluded that the lateral pin photodiode in the Si0.8Ge0.2/Si superlattice layer holds tremendous promise as a thin-film photosensor offering high sensitivity throughout the visible spectrum.

High-speed monolithic coherent optical receiver integrated on InP substrate

A monolithic coherent receiver having a directional waveguide coupler and a balanced pair of lateral pin photodiodes was fabricated. The lateral pin photodiode has an improved structure, exhibiting a 3dB bandwidth of 2 GHz. Heterodyne detection with this monolithic receiver was demonstrated at l.8GHz and 2.3GHz.