Avalanche multiplication in Al/sub x/Ga/sub 1-x/As (x=0 to 0.60)

Abstract

Abstract-Electron and hole multiplication characteristics, and have been measured in Al Ga 1 As ( =0 -0.60) homojunction p + -i-n + diodes with i-region thicknesses, from 1 m to 0.025 m and analyzed using a Monte Carlo model (MC). The effect of the composition on both the macroscopic multiplication characteristics and microscopic behavior is therefore shown for the first time. Increasing the alloy fraction causes the multiplication curves to be shifted to higher voltages such that the multiplication curves at any given thickness are practically parallel for different The ratio also decreases as increases, varying from 2to 1as increases from 0 to 0.60 in a =1 m p + -i-n + The Monte-Carlo model is also used to extract ionization coefficients and dead-space distances from the measured results which cover electric field ranges from 250 kV/cm-1200 kV/cm in each composition. These parameters can be used to calculate the nonlocal multiplication process by solving recurrence equations. Limitations to the applicability of field-dependent ionization coefficients are shown to arise however when the electric-field profile becomes highly nonuniform.

Effect of dead space on avalanche speed [APDs]

“…1. The ionization coefficients and threshold energies used in these and all subsequent simulations in this work are for GaAs and are taken from [21]. The RPL results agree with those given by the recurrence equations formulated by Hayat et al [6], confirming that for calculations of spatial multiplication statistics, RPL is equivalent to the recurrence technique, which has been used to successfully model photomultiplication and excess noise measurements [3], [5].…”

“…2. Since calculations using ionization coefficients and threshold energies for GaAs in [21] suggest and in a 0.2 m APD with , the value of chosen here is not unreasonable. A fixed ratio of is used to allow clear comparisons between results with and without dead space.…”

Gain-bandwidth product optimization of heterostructure avalanche photodiodes

“…In a hard-threshold dead-space model, the expressions for the pdfs are given by [20] (4) (5) The position-and material-dependent electron dead space is calculated using the following implicit equation [20]: (6) where is the electron ionization threshold energy for the material occupying the location . Similarly, the hole dead space is obtained using (7) In this paper, the model used to calculate the impact ionization coefficients, and , along with the threshold energies for electron and for holes (viz., , and ) correspond to those developed by Saleh et al [24] for GaAs and Plimmer et al [25] for Al Ga As, as shown in Table I. Fig.…”

EFFECT OF MULTIPLICATION REGION MOLE FRACTION ON CHARACTERISTICS OF ALxGA1-xAS-APDS IN THE LINEAR AND GEIGER

“…To see the effects of change of multiplication region mole fraction on the characteristics of avalanche photodiodes we use the nonlocalized ionization coefficient model (width independent ionization coefficient) derived by Plimmer et al [14] and DSMT introduce in the previous section to characterize the behavior of the Al x Ga 1−x As-APDs. In our calculations, we assumed a constant electric field profile within the multiplication region and used the simple approximation V = εW for the reverse bias voltage.…”

“…Change of multiplication region mole fraction exchange the ionization coefficient parameters. Plimmer et al [14] introduced the mole fraction dependence of α and β in Al x GaAs 1−x .In this paper we considered the change of multiplication region mole fraction and used the width independent ionization coefficient introduced by Plimmer et al [14] for providing the general numerical analysis to calculate the gain, breakdown probability, breakdown voltage, single photon quantum efficiency, performance factor, and excess noise factor of Al x Ga 1−x As APDs. On the other hand the effect of multiplication region width while we change the multiplication region mole fraction has been study.…”