Growth and characterization of SiGeSn pseudomorphic layers on 200 mm Ge virtual substrates

Abstract

In this contribution, we report on the growth of pseudomorphic SiGeSn layers on 2.5 μm thick Ge virtual substrates on Si(001). A single wafer reduced pressure chemical vapor deposition reactor was used for the 100 Torr epitaxy of those layers, with digermane (Ge 2 H 6 ), tintetrachloride (SnCl 4 ) and disilane (Si 2 H 6 ) as precursors. Detailed analyses regarding the growth kinetics, layer composition and surface morphology as function of the growth temperature and Si 2 H 6 flow are presented. As the temperature increases we have, for the same precursor flows, a Si content increase and a Sn content decrease. The activation energy associated with the exponential increase of the SiGeSn growth rate with the temperature, 9.5 kCal.mol −1 , is close to that of GeSn (10.6 kCal.mol −1 ). Furthermore, we show that the addition of Si 2 H 6 to the gaseous mixture results (besides the expected Si content increase) in a Sn content increase and a Ge content decrease. This study yields a better understanding of the growth of SiGeSn compound semiconductors.

PECVD Growth of Composition Graded SiGeSn Thin Films as Novel Approach to Limit Tin Segregation

“…2). 12,23,24 This indicates that the films are polycrystalline in nature. The peak intensity profile for the polycrystalline films is similar to that of powder Ge.…”

“…As a result, the peak belonging to the Si (100) plane at 69.12°is observed as a broad peak in the scans instead of as a sharp peak. Diffraction peaks corresponding to the (111), (110), (311) and (004) SiGeSn planes are observed for the all the films (as marked in the Fig.2) 12,23,24. This indicates that the films are polycrystalline in nature.…”

Growth of SiGeSn Thin Films Using Simplified PECVD Reactor towards NIR Sensor Devices

“…The peak intensity profile for the polycrystalline films is similar to that of powder Ge (except the (004) peak intensity is higher on account of the Si (100) substrate used for film growth). 14 This indicates that the film has a nearly randomly oriented structure. The reason for the polycrystallinity is the non-UHV atmosphere during the deposition of the thin films.…”

“…12 Si incorporation at low temperatures is challenging due to the low decomposition rate of commercially available Si precursors compared to that of Ge precursors. 14 Therefore, specialized growth approaches employing expensive processes (such as Ultra High Vacuum-Chemical Vapor Deposition and Pulsed Laser Epitaxy) and exotic precursors (such as higher order germanes and silanes) have to be utilized to grow the alloy. 15 In this work, we report on the deposition of polycrystalline SiGeSn thin films on buffer-free Si using an in-house assembled simplified Plasma Enhanced Chemical Vapor Deposition (PECVD) reactor.…”

GeSn heterostructure micro-disk laser operating at 230 K

“…Such layers had to be capped with lower tin content layers without any growth interruption, which would have been mandatory during the temperature ramping-up prior to SiGeSn encapsulation. We have however progressed concerning the growth of SiGeSn layers at various temperatures and should be able, in the near future, to grow SiGeSn barriers beneath and just above such GeSn 16.0% layers [26].…”