선택성장영역 크기에 따른 InGaN/GaN 다중양자우물 청색 MOCVD-발광다이오드 소자의 특성

Abstract

(Received October 12, 2011)(Revised October 24, 2011)(Accepted November 11, 2011)Abstract In general, the fabrications of the LEDs with mesa structure are performed grown by MOCVD method. In orderto etch and separate each chips, the LEDs are passed the RIE and scribing processes. The RIE process using plasma dryetching occur some problems such as defects, dislocations and the formation of dangling bond in surface result in declineof device characteristic. The SAG method has attracted considerable interest for the growth of high quality GaN epi layeron the sapphire substrate. In this paper, the SAG method was introduced for simplification and fabrication of the highquality epi layer. And we report that the size of selective area do not affect the characteristics of original LED. Thediameter of SAG circle patterns were choose as 2500, 1000, 350, and 200µm. The SAG-LEDs were measured to obtainthe device characteristics using by SEM, EL and I-V. The main emission peaks of 2500, 1000, 350, and 200µm were 485,480, 450, and 445 nm respectively. The chips of 350, 200µm diameter were observed non-uniform surface and resistancewas higher than original LED, however, the chips of 2500, 1000µm diameter had uniform surface and current-voltagecharacteristics were better than small sizes. Therefore, we suggest that the suitable diameter which do not affect thecharacteristic of original LED is more than 1000µm.Key wordsSelective area growth, InGaN/GaN, Multi quantum well, MOCVD, Band-filling effect, Screening effect