The doping of silicon with boron by rapid thermal processing

Abstract

An alternative doping process to ion implantation for the production of very shallow p'-n junctions has been investigated. The n-type silicon wafers covered with a boron-doped silicon oxide were submitted to thermal cycles with incoherent light radiation to temperatures between 900 and 1250 "C for times ranging from 20 to 120 S, in order to promote boron in-diffusion. The samples were characterised by sheet resistance measurements combined with sequential layer removal to obtain the carrier concentration-depth profiles. The results show the formation of a boron-rich surface layer above the normal boron solubility levels and a linear dependence of the sheet conductance on diffusion time, which suggests a chemical reaction at the silicon surface is the controlling factor for the boron in-diffusion. Moreover it was demonstrated that defect-free p*-n junctions with a junction depth as shallow as 50 nm are readily obtained.

Rapid Thermal Flow of PSG Films in Vacuum Using a Graphite Heater

“…This situation corres p o n d s to t h e r m a l t r e a t m e n t s of 1000~ for ~p p r o x i m a t e l y 120s, 1100~ for 10s, a n d 1200~ for a p p r o x i m a t e l y 3s (8,13,14) and ~ is the surface-free energy that is primarily dependent on the surface area on the PSG profile (12,16). The value of ~ is approximately constant considering that the initial PSG profiles are supposed to be near to a large flat plane such as the flow process is only a small pertubation on the surface (12).…”

Strong in-plane anisotropy in the electronic properties of doped transition metal dichalcogenides exhibited in W1−xNbxS2

“…gating and adatoms), but the traditional approach, as in the semiconductor industry, remains substitutional doping with acceptor or donor impurities. Analogy to use of B as an acceptor and P as a donor for silicon [17][18][19] , suggests (Nb, Ta) as hole donors 4,20,21 and (Tc, Re) as electron donors 22,23 for MX 2 devices. Aliovalent dopant impurities can be expected to have strong effective interactions between impurity atoms that may influence dopant distributions.…”

Strong In-plane Anisotropy in the Electronic Properties of Doped Transition Metal Dichalcogenides exhibited in W1-xNbxS2

“…gating and adatoms), but the traditional approach, as in the semiconductor industry, remains substitutional doping with acceptor or donor impurities. Analogy to use of B as an acceptor and P as a donor for silicon, [13][14][15] suggests (Nb, Ta) as hole donors 4,16 and (Tc, Re) as electron donors 17 for MX 2 devices. Aliovalent dopant impurities can be expected to have much stronger effective interactions between impurity atoms that may influence dopant distributions between atoms.…”