Excimer laser induced deposition of InP and indium-oxide films

Abstract

InP and In-oxide films have been deposited on quartz, GaAs, and InP substrates by excimer laser induced photodecomposition of (CH3)3InP(CH3)3 and P(CH3)3 vapors at 193 nm. The oxide film refractive index and stoichiometry are close to In2O3. Phosphorus incorporation in the films was greatly enhanced by focusing the laser beam to promote multiple-photon dissociation processes. These conditions also lead to enhanced carbon inclusion in the films, due to formation of species such as CH and CH2 in the gas phase. However, this carbon inclusion could be suppressed by focusing the beam onto the surface at normal incidence. In the irradiated zone InP could be deposited with P(CH3)3-to-(CH3)3InP(CH3)3 ratios of only ∼1:1. The technique offers several potential advantages over conventional metalorganic chemical vapor deposition, including lower temperature, enhanced rates, safer gases, and three-dimensional film composition control. Strong atomic In emission is observed in the gas phase above the depositing film, due to a multiple photon dissociation process. Gas phase fluorescence from P, CH, and C was also observed. These emissions give insight into the photodecomposition mechanism and also serve as a monitor of metalorganic precursor concentrations.

Mercury‐Sensitized Photochemical Vapor Deposition of Gallium Arsenide on Quartz

“…The particular material used to construct these lamp envelopes did not permit the emission of the 185 nm radiation line. It has been demonstrated that the Hg-photosensitized decomposition of arsine proceeds as follows (lO) Hg + h~ (254.3 rim) --) Hg* [1] Hg* + AsH3--~ AsH2 + H + Hg [2] AsH2 ~ As + H2 [3] leading to the formation of As films. Here Hg* represents the excited Hg atom and hv represents the photon energy.…”

“…There have been few papers in the past where a low resistivity p-type crystal has been grown. Recently, Yasuda et al (1) succeeded in preparing a p-type crystal and also p-n junction by MOCVD method.…”

“…Flexibility resulting from factors such as spatially selective deposition and lower deposition temperatures may further enhance the applicability of this material. The use of photochemical means to achieve deposition of III-V compound semiconductors has received some attention in recent years (1)(2)(3)(4)(5)(6)(7). Photochemical vapor deposition techniques offer potential control over delineating the area of deposition and permit reduction in the degree of substrate heating necessary for film deposition.…”

UV-assisted synthesis of indium nitride nano and microstructures

“…20 However, UV-photochemical vapour deposition (UV-CVD) has been successfully used in the past to deposit numerous metals, insulators, and semiconducting lms. [21][22][23] In photochemical reactions, absorption of light by a reactant molecule enables an inaccessible reaction path to occur by bringing the reactants to the necessary activation energy and also by changing the symmetry of the reactant's electronic conguration. 24 Medium pressure mercury UV lamps are important radiation sources for photochemical applications.…”

Design of Transparent Indium Tin Oxide-Based Interdigitated Fingers for Metal Semiconductor Metal Photodetector

“…Among the various possible TCOs, indium tin oxide ͑ITO͒ is commonly used as a contact for transparent electrodes due to its excellent properties in transmittance, electrical conductivity, substrate adhesion, hardness, and chemical inertness. [1][2][3][4][5][6][7][8] A variety of ITO deposition techniques have been reported, including electron-beam evaporation, 9 dc or radio frequency ͑rf͒ sputtering, 10 reactive ion plating, 11 chemical vapor deposition, 12 and pulsed laser deposition. 13 ITO has been used for interdigitated finger electrodes on metalsemiconductor-metal photodetectors ͑MSM͒, improving the photon responsivity by minimizing blocking of incoming light by the finger electrodes.…”