High-speed photodetector with controlled relocation of carrier density peaks

Abstract

Nowadays, metal interconnections are near to the physical limit of their application in integrated circuits due to the continued scaling of transistors and an increase in the integration degree. An optoelectronic approach to the solution of this problem considers optical systems as advanced on- and inter-chip connections. Our previous papers were aimed at the development of an injection laser with a double AIIIBV heterostructure and a functionally integrated optical modulator. Owing to the principle of controlled relocation of carrier density peaks within quantum regions, the laser-modulator can generate optical signals with terahertz modulation frequencies. To detect such signals, a technologically compatible photodetector with subpicosecond response time is needed. In this paper, we propose a novel design of AIIIBV high-speed photodetector for optical interconnections in integrated circuits. It is based on the same relocation principle as the laser-modulator and includes a traditional p-i-n photosensitive junction and an orthogonal control heterostructure that displaces the peaks of electron and hole densities into special low-temperature-grown regions during the back edge of a laser pulse. We developed a numerical model of the photodetector with controlled relocation of carrier density peaks and estimated the duration of the photocurrent back edge.