Epitaxial Si-Based Tunnel Diodes

Published

December 1, 2000

Author(s)

P E. Thompson, K D. Hobart, M E. Twigg, S L. Rommel, N Jin, P R. Berger, R Lake, A C. Seabaugh, P Chi, David S. Simons

Abstract

Tunneling devices in combination with transistors offer a way to extend the performance of existing technologies by increasing circuit speed and decreasing static power dissipation. We have investigated Si-based tunnel diodes grown using molecular beam epitaxy (MBE). The basic structure is a p⁺ layer formed by B delta doping, an undoped spacer layer, and an n⁺ layer formed by Sb delta doping. In the n-on-p configuration, low temperature epitaxy (300 C - 370 C) was used to minimize the effect of dopant segregation and diffusion. In the p-on-n configuration, a combination of growth temperatures from 320 C to 550 C was used to exploit the Sb segregation to obtain a low Sb concentration in the B-doped layer. Post-growth rapid thermal anneals for 1 minute in the temperature interval between 600 C and 825 C were required to optimize the device characteristics. J_p, the peak current density, and the peak-to-valley current ratio (PVCR), were measured at room temperature. An n-on-p diode having a spacer layer composed of 4 nm Si_0.6Ge_0.4, bounded on either side by 1 nm Si, had a J_p = 2.3 kA/cm² and PVCR = 2.05. A p-on-n tunnel diode with an 8 nm Si spacer (5 nm grown at 320 C, 3 nm grown at 550 C) had a J_p = 2.6 kA/cm² and PVCR = 1.7.

Citation

Thin Solid Films

Volume

380

Issue

No. 1-2

Pub Type

Journals

Keywords

delta doping, epitaxy, silicon, silicon-germanium, tunnel diodes

Citation

Thompson, P. , Hobart, K. , Twigg, M. , Rommel, S. , Jin, N. , Berger, P. , Lake, R. , Seabaugh, A. , Chi, P. and Simons, D. (2000), Epitaxial Si-Based Tunnel Diodes, Thin Solid Films (Accessed April 25, 2024)