Atomically Controlled Technology for Future Si-Based Devices

Abstract

One of the main requirements for Si-based Ultrasmall device is atomic-order control of process technology. Here we show the concept of atomic-level processing based on atomic-order surface reaction control. The main idea of the atomic layer approach is the separation of the surface adsorption of reactant gases from the reaction process. Self-limiting formation of 1-3 atomic layers of group IV or related atoms in the thermal adsorption and reaction of hydride gases (SiH 4 , GeH 4 , NH 3 , PH 3 , CH 4 and SiH 3 CH 3 ) on Si(100) and Ge(100) are generalized based on the Langmuir-type model. Si or SiGe epitaxial growth over the N, P and B layer already-formed on Si(100) or SiGe(100) surface is achieved. It is found that higher level of electrical P atoms exist in such film, compared with doping under thermal equilibrium conditions. Furthermore, the capability of atomically controlled processing for doping of advanced devices with critical requirements for dose and location control is demonstrated for the base doping of SiGe:C heterojunction bipolar transistors (HBTs). These results open the way to atomically controlled technology for ultra-large-scale integrations.

Atomically Controlled Processing for Group IV Semiconductors by Chemical Vapor Deposition

“…Atomic layer doping (ALD) is performed by epitaxial growth over the material already-formed on Si(100) or SiGe(100) surface. [9][10][11]54,55) The heteroepitaxial growth of the Si/half atomic layer of N/Si(100), 10,[56][57][58] the Si/half atomic layer of P/Si(100), 10,59,60) the SiGe/single atomic layer of B/SiGe(100), 15,54,55) the SiGe/0.8 atomic layer of C/SiGe(100) 11) and the Si/0.03 atomic layer of W/ Si(100) 61,62) has been achieved. In this section, atomic layer doping of N, P, and B are reviewed and the characteristics are discussed.…”

“…1). Based on the investigation of surface reaction processes, the concept of atomic layer process control 3,6,7,[9][10][11] has been demonstrated for high-performance Si 0:65 Ge 0:35 -channel p-type MOS fieldeffect transistors (pMOSFETs) with a 0.12 mm gate length by utilizing in-situ impurity-doped Si 1Àx Ge x selective epitaxy on the source/drain regions at 550 C, 12) for ultrathin P barriers in infrared SiGe/Si heterojunction internal photoemission detectors, 13) and for B and P base doping in npn and pnp hetero-bipolar transistors (HBTs). [14][15][16] In this review, we describe ultraclean low-temperature low-pressure CVD processing using SiH 4 and GeH 4 gases.…”

“…Atomic-level control has been realized for epitaxy (Si, Ge), deposition (W, nitride), doping (P, B, C) and layer-by-layer etching. [9][10][11] The final goal of the atomic layer approach is the generalization of the atomic-order surface reaction processes and the creation of new properties in Si-based ultimate small structures which will lead to nanometer scale Si devices as well as Si-based quantum devices (Fig. 1).…”

A Study on B Atomic Layer Formation for B-Doped Si1-xGex(100) Epitaxial Growth Using Ultraclean LPCVD System

“…Atomically controlled doping in the group IV semiconductor heterostructure is a key technology to fabricate high-performance ultrasmall semiconductor devices (1). For the formation of nanometer scale B-doped structure, atomic-layer doping of B in Si 1-x Ge x epitaxial growth has been performed, although the surface reaction of B 2 H 6 on Si 1-x Ge x is not self-limited at higher temperatures above 150 o C (2,3).…”

“…For the formation of nanometer scale B-doped structure, atomic-layer doping of B in Si 1-x Ge x epitaxial growth has been performed, although the surface reaction of B 2 H 6 on Si 1-x Ge x is not self-limited at higher temperatures above 150 o C (2,3). Moreover, utilizing the B atomic-layer doping technique to control dopant dose and location control in base doping, high-performance SiGe:C heterojunction bipolar transistor (HBTs) had been demonstrated (1,4). In the previous works, by self-limited reaction of B 2 H 6 on Si 1-x Ge x at a low temperature of 100 o C has been reported (4).…”