کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1795940 | 1524485 | 2007 | 5 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Improvement of crystalline quality of N-polar AlN layers on c-plane sapphire by low-pressure flow-modulated MOCVD Improvement of crystalline quality of N-polar AlN layers on c-plane sapphire by low-pressure flow-modulated MOCVD](/preview/png/1795940.png)
The growth of N-polar AlN layers on c-plane sapphire is reported. Low-temperature AlN (LT-AlN) layers were used as seeding buffer layers with pre-nitridation for sapphire. To avoid strong vapor-phase reaction between trimethylaluminum (TMA) and ammonia (NH3) and to improve the crystalline quality, low-pressure flow-modulated (FM) metal-organic chemical vapor deposition (MOCVD) technique was introduced with careful optimization of the FM sequence. The surface morphologies and the crystalline quality defined by the X-ray diffraction (XRD) (0 0 2) and (1 0 0) rocking curve measurements strongly depended on the LT-AlN thickness and on the TMA coverage per cycle of the FM growth. The sample showing the best XRD data with a good morphology was almost completely etched in aqueous KOH solution owing to N-polarity. From the plan-view transmission electron microscopy (TEM) observation, the dislocation density was counted to be about 3×1010 cm−2.
Journal: Journal of Crystal Growth - Volume 298, January 2007, Pages 336–340