The preparation, characterization and applications of silicon nitride thin films

A theoretical low-frequency noise model for the epitaxial-channel surface field-effect structure is presented where random modulation of the channel conductance arises from fluctuation of charges trapped at the oxide trap states near the Si-SiO 2 interface. In this model, charge fluctuation in the oxide traps arises from carrier tunneling between the fast interface surface states and the oxide trap states. A second fluctuation, at higher frequencies, arises from the random thermal emission and capture of electrons and holes at the fast interface states through the thermal or Shockley-Read-Hall process. Different oxide trap densities were introduced into the interface region of the metal-oxide-silicon field-effect structures using a carefully controlled and reproducible oxygen heat treatment technique. Energy distributions of the oxide trap densities are obtained from capacitance measurements. Humps are observed between the flat band and the onset of strong surface inversion (lower half of the bandgap) in both the noise power and the oxide trap density versus gate voltage (or surface band bending) plots. Theoretical noise power calculations using the experimental oxide trap density profile from the capacitance-voltage data agree very well with the experimental noise humps in both magnitudes and fine structures. It is shown that the frequency spectra of noise depend strongly on the oxide trap density profile in the oxide. It is suggested that the oxide traps are due to the excess oxygen at the SiO 2 -Si interface.

Theory and experiments on surface 1/f noise

The model proposed by McWhorter for low‐frequency noise in metal‐oxide‐semiconductor field‐effect transistors (MOSFETs) assumed that the 1/f spectrum was due to the sum of the Lorentzian spectra produced by modulation of the channel current by charge state transitions at traps in the adjacent oxide. Considerable evidence for the presence of such current modulation has been accumulated recently. From extensive studies of random telegraph signal (RTS) current waveform in many types of devices we present new results on the dependence of the amplitudes and characteristic times on device geometry, bias, and temperature. Based on these results we propose a comprehensive model for the generation of RTS waveforms in semiconductor devices. The amplitude modulation of a steady current in a device due to the trapping of a carrier at a fixed site is derived by applying an extension of Ramo’s theorem. The characteristic times of the RTS are derived from the properties of the trap, the carrier concentrations, and tempe...

A physical model for random telegraph signal currents in semiconductor devices

A physical model for burst noise in p−n junction devices is presented. It is proposed that burst noise results when the current through a defect is modulated by a change in the charge state of a single recombination-generation center located adjacent to the defect. The burst noise amplitude and pulse widths are related to the basic properties of the recombination-generation center and the defect. The model leads to a simple interpretation of the equivalent circuit for diodes which exhibit this type of noise.

Physical model for burst noise in semiconductor devices

Publisher Summary This chapter highlights noise as a measure of quality and reliability in electronic devices The chapter attempts to describe what mechanisms have been well established as a source of noise related to the defective or nonideal nature of electronic devices This chapter is devoted to an account of the success that has been obtained in using noise as a nondestructive indicator of reliability The chapter is mainly concerned with a review of the properties of noise and some of the general principles behind the specific mechanisms Noise arises from many possible defects so that monitoring this single quantity can detect the presence of one or more of many different defects It is, therefore, necessary to be careful in interpreting noise results to ensure that a correct mechanism is assigned to the noise, and even greater care is necessary in comparing noise results among different specimens, because the origins and characteristics of the noises may be completely different As many of the detailed mechanisms for the production of the excess noise are becoming understood, the use of noise as an analysis quantity can increase

Electrical Noise as a Measure of Quality and Reliability in Electronic Devices

Burst noise has been investigated in forward-biased silicon diodes and transistors. To separate surface effects from bulk effects, measurements were performed on gate-controlled devices. Both gate-voltage-dependent and gate-voltage-independent burst noise were observed. Burst noise under forward bias conditions has been characterized in terms of the bias across the p-n junction. From this characterization simple equivalent circuits are presented for diodes and bipolar transistors which model the main features of burst noise in these devices. Analytical expressions for the burst noise spectral distributions are developed and compared with experiment.

Characterization of burst noise in silicon devices

Simple charge control theory is used in conjunction with the Early effect to determine the base transport factor of bipolar transistors. Experimental data show that the base profiles of double-diffused transistors can be characterized by an exponential function. It is also shown that it is possible to determine neutral region base lifetimes using the technique described.

Simple determination of the base transport factor of bipolar transistors

The common emitter I C  V CE characteristics of double-diffused transistors at low collector-to-emitter biases are discussed. The observed decrease in emitter-to-collector resistance is qualitatively described by existing models for base-widening and lateral injection. The quantitative nature of the reduction in resistance depends on the bulk lifetime and dimensions of the transistor. The decrease in resistance is shown to take place prior to the onset of saturation.

R.J. Whittier

Papers

Physical model for burst noise in semiconductor devices

Characterization of burst noise in silicon devices

Simple determination of the base transport factor of bipolar transistors

The effects of lateral injection and base-widening on the high current-low voltage characteristics of transistors