Native defects in gallium arsenide

Abstract

We describe information which has been obtained on point defects detected in various types of GaAs materials using electron paramagnetic resonance as well as electrical and optical techniques. From a comparison of their characteristics and those of simple intrinsic defects (As and Ga interstitials, vacancies and antisites) it is concluded that native defects are not simple intrinsic defects, with the exception of the antisites, but complexes formed by the interaction of such defects between themselves or with impurities. Particular emphasis is given to the As antisite complexed with an As interstitial, the so-called EL2 defect which plays a major role in the electrical properties of bulk materials. Differential thermal analysis, positron annihilation, and x-ray diffraction demonstrate that bulk materials contain a large concentration of vacancy-related defects and As precipitates located along dislocations which play the role of gettering centers. Presumably, bulk materials also contain other As clusters of various sizes although only the smallest ones (EL2) have been detected. All these As clusters are sources of As interstitials which play an important role in thermal treatments. As to semi-insulating materials, their electrical properties result mainly from the compensation between the double donor, called EL2, associated with the As antisite and the double acceptor ascribed to the Ga antisite.

Characterization of deep level traps responsible for isolation of proton implanted GaAs

“…Pp3 exists in the as-grown material ͓Fig. 1͑b͔͒ and corresponds to HB4 observed in epitaxial layers 18 Tables I and II͒. energy is similar to H1 16 trap level, known as a Frenkel pair defect. Table II summarizes the observed deep levels in p-type GaAs.…”

“…One is that EL2 is an intrinsic and complex lattice defect with an arsenic antisite As Ga as a core and arsenic interstitial As i as a neighbor, forming pair as a result of a Coulomb interaction. 18 The other is that EL2 is simply an isolated arsenic antisite As Ga or gallium vacancy-arsenic interstitial (V Ga As i ) complex. 19 Pn2 and Pn3 peaks were resolved, using the method shown in Fig.…”

“…1͑a͔͒. It is known like E level 18 and was measured in as-grown MOCVD material. After irradiation and during post-irradiation annealing Pn2 is transformed into the P3 level well known from the literature.…”

“…Epitaxial layers of n-type and p-type GaAs were grown on epi-ready vertical gradient freeze Si-doped ͑carrier concentration of 2ϫ10 18 cm Ϫ3 ) and Zn-doped ͑carrier concentration of 6 -8ϫ10 18 cm Ϫ3 ) ͗100͘ GaAs with 2°off normal toward the ͑110͒ using the Australian National University ͑ANU͒ metalorganic chemical-vapor deposition ͑MOCVD͒ reactor. Trimethylgallium was used as the group III source with H 2 as the carrier gas and arsine was used as the group V source.…”

To a Question on the Determination of Charge Carriers Capture Cross Section by DLTS Method

“…Êëþ÷åâûå ñëîâà: DLTS, ñå÷åíèå çàõâàòà, DLTS ñïåêòðîìåòð çàõîïëåííÿì íîñ³ÿ äåôåêòîì [9]. Âèñîòó ïîòåí-ö³àëüíîãî áàð'ºðà íàâêîëî ïîðóøåííÿ ñòðóêòó-ðè ïîòð³áíî âðàõîâóâàòè ³ ïðè âèì³ðþâàííÿõ ïðîô³ëþ êîíöåíòðàö³¿ äåôåêòó ìåòîäîì DLTS [1], îñê³ëüêè ïåðåäáà÷óâàíà ïðè öüîìó âàð³à-ö³ÿ çâîðîòíüîãî çì³ùåííÿ âíàñë³äîê åôåêòó Ïóëà -Ôðåíêåëÿ ïðèçâîäèòü äî çì³íè ³ìîâ³ð-íîñò³ åì³ñ³¿ íîñ³¿â e n (e h ).…”