Electrical characterization of Al-SiO2-Si (N-type) tunnel structures. Influence of LPCVD and LPO2 oxide growth technologies on the properties of the Si-SiO2 interface

Electronic properties of Al-SiO2-(n or p) Si MIS tunnel diodes

“…The reverse characteristics show sometimes a « threshold effect » particularly for devices without annealing (curve 2 in Fig. 2a) : the current is first very low and then remains constant for bias lower than -0.3 V. The authors have explained this effect in a previous paper by introducing electrostatically acting donor-like interface states in the vicinity or below of the semiconductor midgap [1]. For the forward characteristics it may be observed that an exponential law is not generally obtained, the characteristics in semilog plot are curved towards the voltage axis.…”

“…We have quoted above, papers giving a detailed numerical and experimental analysis of MIS tunnel diodes on p wafer [4,5]. In the present work we use a simulation model [1,8] developed for an n type semiconductor, particularly to study the dispersion of I-Y characteristics on n type silicon. The results obtained using this model are presented in the next section (4.3.2).…”

“…-In MIS tunnel structures with a very thin oxide layer the mechanisms for current conduction are : tunnelling between the metal and the majority carrier energy band in the semiconductor, tunnelling between the minority carrier energy band, tunnelling between the metal and surface state levels (surface states act as recombination generation centres and provide additional tunnelling paths between the metal and the semiconductor). From these considerations, a simulation model for the working of MIS tunnel structures has been developed by the authors [1,8]. In this model the usual differential equations describing the potential distribution and the transport of free carriers are replaced by a nonlinear algebric equation system : the numerical solution becomes easier and it needs shorter computation time.…”

“…Typical example is shown in figures 6a and b. 5.2 EVALUATION oF Nss AND Vs. -The conductance method of Nicollian and Goetzberger [1,[11][12][13] is suitable for the determination of interface state density N,, in MIS structure with very thin oxide layer. The necessary equivalent circuits of the MIS diode for this evaluation are shown in figures 7c and d. The n devices are in depletion in low reverse bias (Fig.…”

“…Using a self consistent numerical model of the working of MIS tunnel diodes developed by the authors [1,2] the dispersion of the current-voltage characteristics of diodes on the same wafer are studied and analysed.…”