Temperature dependence of silicon doping of GaAs by SiH4 and Si2H6 in atmospheric pressure metalorganic chemical vapour deposition

Abstract

Document VersionPublisher's PDF, also known as Version of Record (includes final page, issue and volume numbers)Please check the document version of this publication:• A submitted manuscript is the author's version of the article upon submission and before peer-review. There can be important differences between the submitted version and the official published version of record. People interested in the research are advised to contact the author for the final version of the publication, or visit the DOI to the publisher's website.• The final author version and the galley proof are versions of the publication after peer review.• The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rightsCopyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.• Users may download and print one copy of any publication from the public portal for the purpose of private study or research.• You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal ? Take down policyIf you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. The temperature dependence of silicon doping in the metalorganic chemical vapour deposition process has been investigated in the temperature range 550 to 800°Cusing silane (SiH4) and disilane (Si2H6). The experiments have been carried out at atmospheric l~l2pressure in a long horizontal reactor. The silicon doping process with both silicon precursors appears to be strongly temperature dependent, with apparent activation energies Eact of 51.4±5.8kcal/mol (2.2±0.3eV) for silane and 45.5±4kcal/mol(2.0±0.2eV) for the doping process with disilane. A thorough analysis is given of the rate determining step in both cases based on the presence of a chemical boundary layer.

Influence of the temperature of the reactor top wall on growth processes in horizontal MOVPE reactors

“…The free height above the susceptor, h, is about 1.6 cm. The results of growth and doping experiments in this system when the water cooler was used have been reported elsewhere [1,6,7]. When the water cooler was used, the temperature of the top wall, Ttop, was so low that elemental arsenic was deposited on the top wall.…”

“…At 200 mbar, the carrier concentration level of the Si-doped GaAs is quite uniform in both cases with and without use of the air top cooler. Doping of GaAs with disilane in MOVPE or the deposition of Si from disilane have been investigated extensively [7,[12][13][14][15], although the uniformity of the carrier concentration of Sidoped GaAs was scarcely studied. It was found that the temperature dependence followed a complicated behavior, but there is a general agreement about the inverse dependence of the doping level on the growth rate.…”

“…At 1 atm all SieH 6 is effectively converted at the susceptor to Sill 4 and the doping takes place via the small amount of Sill: which is determined by the equilibrium Sill 4 ~ Sill 2 + H:, so that the concentration of the input dopant in the MOVPE reactor is almost constant showing no apparent depletion of the "disilane" at all [7]. The deposition of Si on the top wall, where the temperature is lower, is negligible because of the high overall activation energy of the process [7]. In contrast, a strong depletion of TMG is always present in the horizontal reactor along the flow direction, as has been demonstrated in Fig.…”