| 학회 | 한국재료학회 |
| 학술대회 | 2009년 봄 (05/21 ~ 05/22, 무주리조트) |
| 권호 | 15권 1호 |
| 발표분야 | 반도체재료 |
| 제목 | Effects of thickness of IGZO channel layer on device performance in oxide TFTs |
| 초록 | Thin-film-transistors (TFTs) that can be prepared at low temperatures have attracted much attention because of the great potential for transparent and flexible electronics. One of the mainstreams in this field is the use of organic semiconductors such as pentacene. But device performance of the organic TFTs is still limited due to low field-effect mobility and rapid degradation after exposing to air. Alternative approach is the use of amorphous oxide semiconductors as a channel. Amorphous oxide semiconductors (AOSs) based TFTs showed the fast technological development, because AOS films can be fabricated at room temperature and exhibit the possibility in application like flexible display, electronic paper, and large solar cells. Among the various AOSs, a-IGZO has lots of advantages because it has high channel mobility, uniform surface roughness and good transparency. [1] The high mobility is attributed to the overlap of spherical s-orbital of the heavy post-transition metal cations. This study demonstrated the effect of the variation in channel thickness from 30nm to 200nm on the TFT device performance. When the thickness was increased, turn-on voltage and subthreshold swing was decreased. The a-IGZO channels and source/drain metals were deposited with shadow mask. The a-IGZO channel layer was deposited on SiO2/p-Si substrates by RF magnetron sputtering, where RF power is 150W. And working pressure is 3M Torr, at O2/Ar (2/28 sccm) atmosphere. The electrodes were formed with electron-beam evaporated Ti (30 nm) and Au (70 nm) bilayer. Finally, Al (150nm) as a gate metal was thermal-evaporated. TFT devices were heat-treated in a furnace at 250 oC and nitrogen atmosphere for 1hour. The electrical properties of the TFTs were measured using a probe-station. The TFT with channel thickness of 150nm exhibits a good subthreshold swing (SS) of 0.72 V/decade and on-off ratio of 1X108. The field effect mobility and threshold voltage were evaluated as 7.2 and 8 V, respectively. |
| 저자 | 우창호, 공보현, 김동찬, 김영이, 안철현, 한원석, 배영숙, 최미경, 조형균 |
| 소속 | 성균관대 |
| 키워드 | IGZO; TFTs; Al:ZnO |
