2 research outputs found
Wafer-Scale, Sub-5 nm Junction Formation by Monolayer Doping and Conventional Spike Annealing
We report the formation of sub-5 nm ultrashallow junctions in 4 inch Si
wafers enabled by the molecular monolayer doping of phosphorous and boron atoms
and the use of conventional spike annealing. The junctions are characterized by
secondary ion mass spectrometry and non-contact sheet resistance measurements.
It is found that the majority (~70%) of the incorporated dopants are
electrically active, therefore, enabling a low sheet resistance for a given
dopant areal dose. The wafer-scale uniformity is investigated and found to be
limited by the temperature homogeneity of the spike anneal tool used in the
experiments. Notably, minimal junction leakage currents (<1 uA/cm2) are
observed which highlights the quality of the junctions formed by this process.
The results clearly demonstrate the versatility and potency of the monolayer
doping approach for enabling controlled, molecular-scale ultrashallow junction
formation without introducing defects in the semiconductor.Comment: 21 pages, 5 figure
Modeling of dual-metal Schottky contacts based silicon micro and nano wire solar cells
We study solar cell properties of single silicon wires connected at their
ends to two dissimilar metals of different work functions. Effects of wire
dimensions, the work functions of the metals, and minority carrier lifetimes on
short circuit current as well as open circuit voltage are studied. The most
efficient photovoltaic behavior is found to occur when one metal makes a
Schottky contact with the wire, and the other makes an Ohmic contact. As wire
length increases, both short circuit current and open circuit voltage increase
before saturation occurs. Depending on the work function difference between the
metals and the wire dimensions, the saturation length increases by
approximately an order of magnitude with a two order magnitude increase in
minority carrier length. However current per surface area exposed to light is
found to decrease rapidly with increase in length. The use of a multi-contact
interdigitated design for long wires is investigated to increase the
photovoltaic response of the devices.Comment: 26 pages, journal pape