Multiwafer atmospheric‐pressure MOVPE reactor for nitride semiconductors and ex‐situ dry cleaning of reactor components using chlorine gas for stable operation

Abstract

We describe an atmospheric‐pressure MOVPE reactor with a capacity of 2 inch by 10 or 3 inch by 8. In this reactor, the parasitic reaction of particulate generation is suppressed by adopting a high‐flow‐speed design. As a result of suppressing of the parasitic reaction, we have also grown GaN at a growth rate of more than 28 μm/hr at atmospheric pressure. It is also important to grow a heterostructure of Al‐containing alloys continuously to enable device applications, while maintaining the proper growth conditions for other layers such as GaN:Mg. An Al0.09Ga0.91N layer has been grown at a growth rate of 1 μm/h at atmospheric pressure. In the production environment, it is also essential to operate a reactor under a stable condition. To this end, we have adopted ex‐situ dry cleaning of all reactor components with deposits on them after every growth run. Dry cleaning was conducted using chemical etching of the deposit by chlorine gas in a hot tube reactor at about 800 °C. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

High Growth Rate MOVPE

“…Surface morphology of all the samples was smooth regardless of the growth rate. Figure 6.12 shows¨-scan X-ray diffraction full width at half-maximum (XRD FWHM) of (002) and (102) reflection as a function of the growth rate [18,19]. In this experiment, the NH 3 flow rate was fixed at 100 SLM, and the TMG supply rate was changed.…”

“…In Fig. 6.11, the growth rate of GaN is shown as a function of normalized TMG supply rate [18,19]. The maximum growth rate was limited only by the limitation of TMG supply.…”

“…The V/III ratio was 300-3,000 according to the growth rate. Each (002) and (102) reflection as a function of growth rate [18] high-temperature-grown GaN was directly deposited on a low-temperature buffer layer. The total thickness of the samples was fixed to about 4 m. The FWHM of symmetric (002) reflection was less than 300 arcsec.…”

“…As a result of the high flow speed, organometallics cannot reach the wafer surface within a reasonable distance from the gas injection nozzle without the suppression effect of the additional top flow of three-layer gas injection [17]. For high-growth-rate GaN, we have developed a production-scale multiwafer reactor (Taiyo Nippon Sanso Corp., SR23K) [18]. The reactor is capable of growing 10 2 in.…”

Review—Review of Research on AlGaN MOCVD Growth

“…Similar study results were obtained by Lundin et al and Touzi et al 53,43 Furthermore, Lundin et al also found that although the Al component decreased with the rise of III-nitride, the rate of decrease in the high ammonia atmosphere was significantly faster than that in the low. In addition, as the ratio of the III-nitride flow rate rose in the total gas, the growth rate also grews, 26,47,49,55,56 thus it was difficult to achieve rapid growth of the AlGaN layer and obtain a high Al component simultaneously by adjusting the III-nitride flow rate.…”