Phosphorus doping of Si and Si1−xGex grown by ultrahigh vacuum chemical vapor deposition using Si2H6 and GeH4

Abstract

100 ppm PH3 diluted in hydrogen is used as the n-type dopant gas in Si and Si1−xGex epilayers grown by ultrahigh vacuum chemical vapor deposition (UHVCVD) using Si2H6 and GeH4. The phosphorus concentration in Si increases linearly at a small PH3 flow rate and becomes nearly saturated at higher flow rates, while the phosphorus concentration in Si1−xGex only shows a nearly linear behavior with PH3 flow rate. The growth rates of Si and Si1−xGex epilayers decrease seriously (∼50%) and slightly (∼10%) with the increase of PH3 flow rate, respectively. These results can be explained by a model based on the enhancement of hydrogen desorption rate at smaller PH3 flow rates and different levels of the effects of phosphorus blocking of surface-activated sites between Si and Si1−xGex epilayers at higher PH3 flow rates.

Characteristics of in-situ phosphorus-doped silicon selective epitaxial growth at atmospheric pressure

“…However, highly doped films obtained using high growth rates have not been obtained because of strong surface segregation of the dopant atoms during growth, which is caused by the formation of symmetric dopant dimers with no dangling bonds on the Si(0 0 1) surface, and which reduces the surface energy significantly [5,6]. The surface segregation reduces the incorporation of dopant atoms into the film, and the segregated dopant atoms passivate the growth surface, thereby reducing the growth rate [7][8][9][10][11][12].…”

Effects of high-concentration phosphorus doping on crystal quality and lattice strain in SiGe HBTs

“…However, to improve HBT performance, a high doping concentration and good crystal quality must be achieved at the same time without using a high-temperature annealing process. Although in-situ phosphorus doping for silicon epitaxial growth has been studied to increase the phosphorus concentration [7][8][9][10][11][12][13], the resistivity of a phosphorus-doped silicon layer has not been sufficiently evaluated. In addition, there are few reports on crystal quality and lattice strain.…”

Low temperature epitaxy of Si and Si1−xGex by utrahigh vacuum-chemical molecular epitaxy

“…9 Recently, a novel ultrahigh vacuum-chemical molecular epitaxy ͑UHV-CME͒ process using a cold-wall reactor with Si 2 H 6 and GeH 4 as source gases has been proposed to obtain high-quality Si/Si 1Ϫx Ge x epilayers and successful SEG capability. [10][11][12][13][14] These are different from the hot wall UHVCVD using SiH 4 and are cold wall UHV-CME using Si 2 H 6 . This article deals with the detailed growth mechanism of the UHV-CME system.…”