Methods for MgSiN2 synthesis

Abstract

Direct synthesis of MgSiN 2 from simple substances was performed in a flow-through system. The sequence of transformations that occur on heating mixed magnesium and silicon powders in flow of nitrogen was determined by X-ray phase analysis.Owing to the increasing interest in semiconductor nitrides, works on synthesis and study of A 2 B 4 N 2 compounds (A 2 , Mg or Zn; B 4 , Si or Ge) have been resumed recently [13 4]. These compounds inherit the structure of a double prototype compound A 3 B 5 (wurtzite or a derivative orthorhombic structure) and, as established by approximate calculations and experiments, must have electronic and optical characteristics closely similar to those of double nitrides.Aluminum nitride can not only be used as a widebandgap semiconductor, but is also regarded now as one of the best materials for substrates of integrated circuits. It has a higher thermal conductivity than the traditionally used aluminum oxide, which makes it possible to raise substantially the degree of integration and speed of response of integrated circuits. Similar applications are possible for a direct analogue of aluminum nitride, MgSiN 2 .The best known methods for synthesis of MgSiN 2 in the form of a powder are based on sintering of mixtures of double nitrides or on nitration of magnesium silicide [4]. The necessity for a preliminary synthesis of double half-products makes process more complex and is a potential source of impurities. This is especially true for the insufficiently chemically stable magnesium nitride.This study was aimed to carry out a direct synthesis of MgSiN 2 from simple substances: Mg, Si, and N 2 . The second goal was to perform a gas-phase synthesis of MgSiN 2 , using volatile Si compounds as a source and relying upon the volatility of Mg.The direct synthesis was performed in a tubular porcelain reactor connected to a gas-distributing system in such a way that a rarefaction, a flow of N 2 or Ar, or a static atmosphere of N 2 could be obtained in it. We used containers made of sintered corundum and inserts for collection of sublimates. The heating was performed in a resistance furnace. The temperature was monitored and controlled using platinum to platinum3rhodium thermocouples. The flow rates of high-purity gases {nitrogen [GOST (State Standard) 9293374] and argon (GOST 101 157379)} was dosed and monitored using valve floating rotameters.The starting mixture was prepared by a thorough dry mixing of powders obtained by mechanical grinding of high-purity ingots of Mg (GOST 6001379) and Si (semiconductor-grade purity, GOST 19 658381). The particle size was 100 3200 mm for the magnesium powder and <10 mm for the silicon powder.The mass of the starting substances, reaction products, and, in some cases, sublimates was measured on an analytical balance. X-ray diffraction patterns were obtained with Fe K = radiation at angles 2q = 203120oC. The processing of the results relied upon the PDF-2 database [5].The Mg : Si ratio in the starting mixture was varied within the range 131.8 to compensate for t...

Ternary Nitride Materials: Fundamentals and Emerging Device Applications

“…Thin-film synthetic methods have simplified the measurement of certain properties, such as electronic transport and optical phenomena, which are difficult to directly probe using bulk material and are crucial for many device applications. While we divide techniques between common PVD and CVD types, many thin-film growth methods do not fall neatly into either category (136)(137)(138)(139). Additional discussion of these techniques can be found in Reference 98.…”

Ternary Nitride Materials: Fundamentals and Emerging Device Applications

“…Thin film synthetic methods have simplified the measurement of certain properties, such as electronic transport and optical phenomena, which are difficult to directly probe using bulk material and are crucial for many device applications. While we divide techniques between common PVD and CVD types, there are many thin film growth methods which do not fall neatly in to either category (136)(137)(138)(139). Additional disucssion of these techniques can be found in Ref.…”

Large‐Scale Synthesis of Magnenium Silicon Nitride Powders at Low Temperature

“…David and Lang 8 first prepared MgSiN 2 in the 1960s by nitridation of Mg 2 Si or mixtures of binary nitrides. In recent years, Grekov and Chernovets 9 prepared MgSiN 2 using Mg/SiH 4 in a N 2 flowing‐through system at 1050°C. Bruls et al 10 .…”