Growth condition dependence of unintentional oxygen incorporation in epitaxial GaN

Abstract

Growth conditions have a tremendous impact on the unintentional background impurity concentration in gallium nitride (GaN) synthesized by molecular beam epitaxy and its resulting chemical and physical properties. In particular for oxygen identified as the dominant background impurity we demonstrate that under optimized growth stoichiometry the growth temperature is the key parameter to control its incorporation and that an increase by 55 °C leads to an oxygen reduction by one order of magnitude. Quantitatively this reduction and the resulting optical and electrical properties are analyzed by secondary ion mass spectroscopy, photoluminescence, capacitance versus voltage measurements, low temperature magneto-transport and parasitic current paths in lateral transistor test structures based on two-dimensional electron gases. At a growth temperature of 665 °C the residual charge carrier concentration is decreased to below 1015 cm−3, resulting in insulating behavior and thus making the material suitable for beyond state-of-the-art device applications.

The Role of Atmospheric Elements in the Wide Band-Gap Semiconductors

“…The SIMS method was used to show [232] that in AlGaN layers more oxygen atoms incorporate into crystal under N-rich than Ga-rich conditions. In the crystal grown by MBE method the oxygen concentration decreases with increasing growth temperature what was confirmed in subsequent research [233,234]. The specific oxygen content in GaN material is observable in the absorption or cathodoand photo-luminescence measurements, as well as by influence on the GaN thermal conductivity [235].…”

Study of GaN Dual-Drain Magnetic Sensor Performance at Elevated Temperatures

“…Also observed in the graph, is decreasing current with increasing temperature, from 300K to 448K, this is likely due to increased scattering mechanisms within the sensor, thereby degrading mobility [14], [15]. There are several sources of scattering in GaN HEMTs, interface roughness between the AlGaN top layer and the 2DEG channel, dislocation scatterings [22], ionized impurity scattering [23] and phonon scattering [7]. Ionized impurity Fig.…”

Нелегированный высокоомный буферный слой GaN для HEMT AlGaN/GaN

“…В [3] сообщается о технической возможности использования в технологии MOCVD пропана для легирования слоев GaN углеродом, однако авторы работы установили негативное влияние пропана на структурное совершенство слоев на начальных этапах роста. В ряде работ сообщается о возможности управления фоновым легированием углеродом [6] и кислородом [7] путем изменения ростовых условий.…”