Design, fabrication and characterization of a novel multiquantum well injection mode device (MQW-IMD) generating a neuron-like, pulse-train output

This work concerns the design, fabrication and characterization of a novel semiconductor device named the Multi-Quantum Well Injection Mode Device (MQW-IMD). The MQW-IMD produces a neuron-like pulse-train output in a simple circuit consisting of a load resistor and capacitor with the characteristics of the pulses similar to those of biological neuron. The MQW-IMD is proposed as an electronic analog to the biological neuron and can be used as a processing element for the implementation of artificial neural networks.;The device consists of n;The performance of the devices was compared with the operation of the biological neuron. The frequency of output pulses showed similar behavior to that of biological neuron, i.e. the pulses started being generated at same threshold voltage the pulse frequency increasing exponentially with the input voltage.;Using the excitatory synaptic circuit employing the MQW-IMD it was demonstrated that the frequency of the output pulses was linearly related with that of the input pulses behavior by the magnitude of the coupling capacitance. This simulates the excitatory synapses of the biological neuron. Inhibitory behavior, temporal summation, and summation over multiple synaptic inputs with individual weighting are also feasible.;The major features of the MQW-IMD are (1) The MQW-IMD operates at room temperature while a similar silicon IMD works only at low temperature such as 4.2 K; (2) The threshold voltage of the frequency characteristic is about 1 V while that of silicon counter part is larger than 10 V; (3) The circuit configuration is simple compared with other current approaches using transistors; (4) Since the power is mostly consumed at the time of pulsing, the power consumption is small. The MQW-IMD and the associated neural circuit are suitable for the high development of artificial neural systems. (Abstract shortened with permission of author.)...