Mixed-source HVPE 방법에 의한 질화물 반도체의 도핑에 관한 연구

Abstract

Group III-nitride semiconductors have been recognized as very important materials for optoelectronic devices. Gallium nitride (GaN) has been one of the most promising materials for blue-ultraviolet (UV) lasers, short wavelength radiation detectors and high-temperature electronic devices. Much of this attention is due to the recent realization of high brightness blue and green light emitting diodes (LEDs) and violet laser diodes (LDs). Almost the nitride based structure and devices have been fabricated using the metalorganic chemical vapor deposition (MOCVD) or hydride vapor phase epitaxy (HVPE) or molecular beam epitaxy (MBE) method, and other growth technique.

The HVPE technique is also useful and popular, because it has a simple growth system and higher growth rate than MOCVD or MBE. The conventional HVPE system is complex and expensive, but mixed-source HVPE system has advantages of simple and economic for the growth of doping GaN layer.

This was achieved successfully, as binary, ternary and quaternary films are demonstrated. Successful n and p-type doping are also demonstrated introducing Te and Mg.

We get a method of the growth of doping GaN layer compounded from the chemical reaction between a NH3 and a tellurium-gallium chloride formed by HCl which is flown over metallic Ga mixed with Te or Mg.

In the growth of n-type GaN layer, silane (SiH4) is commonly used as a source material for n-type doping by MOCVD method. Also, Si is commonly used as a source material for n-type doping and Te is commonly used as the GaTe or PbTe sources. The formation of p-type GaN layer is the key technology in developing these emitting devices. The acceptor commonly used for p-type doping of nitrides is Mg, which is characterized by a relatively large thermal activation energy (120 ~ 200 meV). P-type conduction was initially obtained in Gan:Mg films which were grown by using metal-organic chemical vapor deposition (MOCVD) and which underwent a post growth low-energy electron-beam irradiation or thermal annealing treatment.

In this paper, the growth of the doping GaN layer is performed using metallic Te or Mg by mixed-source HVPE as a new attempt. We suggest that the mixed-source HVPE method is possible to be one of the growth methods of III-Nitride.