臺灣博碩士論文加值系統

為了製造綠色的薄膜電激發光元件,以射頻磁控濺系統研製高品質的 ZnS:
TbOF 薄膜,並對其結晶性,氧氣含亮,發光特性與激發激制謚竣@系列的研
究.在以功率密度4.39 W/cm2,基板溫度175C,氣體壓力2X10(-3)torr 及做
一小時300C-320C 退火所得之薄膜具有較佳之結晶性.另一方面,介電薄
膜 Ta2O5 與 HfO2之最佳濺鍍條件分別為功率密度 3.07 與 5.26 W/cm2,
基板溫度均為 125 C,氣體壓力為5X10(-3) 與6X10(-3)torr,及做250C一
小時退火處理.以 EPMA 量測薄膜的組成,其 Tb/F 的比值約為1,但是 O/
Tb的比值卻明顯受到濺鍍條件的影響.氧原子將佔據晶格位置而影響薄膜
特性.由 EL 與 PL 光譜的變化中,可以了解氧原子將會抑制再結合作用的
特性. 我們將使用具有金屬-絕緣層-半導體為結構的元件,得到臨界電壓
為 30V,外加電壓 140V 及 1kHz 正旋波激發下,有最大亮度 250 cd/m2;
同時也確定 TbOF 發光中心要比 TbF有更高的效率.這種在亮度及效率上
的改善,是因為 Tb 離子中非幅射過程的減少,及因氧原子介入晶格使得衝
擊面積增加,而在Tb的晶格位置上產生更多有效的電子電洞對所造成的.

In order to fabricate the high-brightness electro- luminescent(
TFEL ) devices, the dependence of crystallinity on growth
conditions of the large-area ZnS thin films deposited by the EL-
MOCVD system have been studied.It was evident from X-ray
diffraction analysis the high-quality ZnS films with a strongly
preferred orientation can be grown with the optimum conditions:
the substrate temperature , the pressure of reaction chamber,
and a mole fraction of H2S to DMZ are 225℃, 30 Torr and 20.
The ZnS films have the best crystallographical quality and the
smoothest surface. In comparison to the other reports, FWHM
which have been reduced below 0.175 in this study show the
approbatory value. The atomic ratio of S/Zn evaluated by
electron probe microanalyzer( EPMA ) is very close to one. And,
the large-area ZnS thin films which have size of 13×19㎝?were
grown by the optimum growth conditions. The uniformity in film
thickness is not obviously affected in the movable direction of
the susceptor and is extremely affected in the unmovable di-
rection of that. Further improvement can be done such as the
adjustment of slits of inlet nozzle, inlet multi-nozzle or re-
production of reduced box installation. Although less than 10%
variation in FWHM was calculated, FWHM variation must be fur-
ther improved too.