The Role of Ion Track Structure on High-Injection Carrier Dynamics in High-Speed Si and III-V Optoelectronic Sensors

Abstract

The role of ion track structure on high-injection carrier dynamics in a high-speed GaAs + + sensor is investigated using laser and high-energy heavy ion microbeams. The results are compared to similar data collected on a Si + + device where Space Charge Screening Effects (SCSE) result in transient shape being dependent on ion track structure. The results collected are discussed within the framework of the Edmonds charge collection model and generalized to III-V optoelectronic sensors.

Temperature Dependence of Spatially Resolved Picosecond Laser Induced Transients in a Deep Submicron CMOS Inverter

“…According to Mavis et al, the collection depth in similar 180 nm structures is m i.e., the maximum possible QNR is m. This translates into a zeroth order solution (the longest duration component in the Fourier series shown in (2)) at least 100 times faster than the 1-2 ns observed in the --Si diodes discussed above [15], [17]. For the structures found in the NMOS regions, the ambipolar period of charge collection is even faster due to the higher minority carrier diffusivity (electrons).…”

“…These screening effects lengthen the pulse width by a degree which depends on device structure, track characteristics and minority carrier diffusivity [7], [15]. Understanding the relative roles of drift and diffusion in determining the pulse shape is important if the effect of temperature on pulse width is to be properly understood.…”

“…The camera can also be used to correct for any thermal expansion in the beam axis using the automated XYZ stage to maintain focus at the same position. Maintaining focus is critical as spot size not only determines image resolution but the transient current pulse shape in some device structures [15], [17]. Average laser energy and LET are measured using a Thorlabs (PM-100 and S130A detector) mounted at a fiducial point on the sample stage.…”

Laser-beam-induced current microscopy of electric fields in natural minerals caused by impurity zonation and structural defects

“…The low-resistance of these junctions has strong ramifications for remote-LBIC imaging. The minority carriers inside the plasma column are screened by the majority carriers and a small drift and longitudinal diffusion current exist to remove this charge [39,40].…”

Simulation of femtosecond pulsed laser effects on MOS electronics using TCAD Sentaurus customized models

“…It is also reported [34] that the charge collection dynamics in the semiconductor is similar, no matter whether the EHP plasma is generated by femtosecond laser or by an ion impact. The radial initial distribution of the EHP plasma is different for each mechanism; however, ambipolar expansion quickly compensates the geometrical differences [35]. Thus, for computational purposes, it can be said that the ion hit and the laser pulse creates similar transport dynamics in the device, provided that their total pair production are the same [5]: Z g las ðr; z; tÞ dV dt ¼ Z g ion ðr; z; tÞ dV dt ð23Þ…”