- 學位論文
銻化物半導體於三五族互補式金氧半元件之應用
Antimonide-based compound semiconductors for III-V CMOS technology
摘要
銻化物半導體因具有大範圍可調變能隙以及三五族半導體間優異的載子遷移率而成為現今相當受矚目的材料，其主要的應用範圍包含7到5奈米以下節點技術之高速低耗能互補式金氧半元件、軍事及生醫產業所使用之紅外線感測器以及綠能產業所發展的太陽能電池。然而，即便目前對於利用銻化物半導體材料來了解操作在超低電壓(小於0.5伏特)下之高效能電晶體的需求與日俱增，卻依然無法得到一個具有低介面缺陷密度以及良好熱穩定性的高介電係數氧化物與銻化(銦)鎵之介面。 在此篇論文中，我們利用分子束磊晶和原子層沉積技術成長氧化釔薄膜於銻化鎵基板上，不僅成功鈍化銻化鎵表面，也得到一個熱穩定性高於攝氏500度以上及具有良好鍵結的高介電係數氧化物與銻化鎵介面。我們透過介面化學鍵結及電性來分別比較利用分子束磊晶和原子層沉積成長之氧化釔薄膜所造成的差異。此外，我們也將探討在不同成長溫度下使用分子束磊晶成長之氧化釔薄膜對於介面特性和元件效能所造成的影響。氧化釔與銻化鎵介面的化學鍵結以及介面化學反應將透過臨場角解析X射線光電子能譜觀察。此外，氧化釔與銻化鎵介面的電性也將藉由電容-電壓特性量測、閘極漏電流-電場特性量測、變溫電導-電壓量測分析以及Gray-Brown方法分析來討論並求得介面缺陷密度。最後，我們製作了自我對準反轉通道層銻化鎵P型金氧半場效電晶體，並得到目前在此相關領域內最佳之元件特性，包括飽和汲極電流 130 A/m、最大轉移電導 90 S/m、低的次臨界擺幅 147 mV/decade以及最大場效電洞遷移率 200 cm2/V-s 於閘極線寬為1 μm的元件中。
並列摘要
Antimonide-based compound semiconductors are emerging materials for the high-speed low-power electronics in complementary metal-oxide-semiconductor (CMOS) industry beyond 7-5 nm node technology, mid-infrared sensors/detectors in military/medical industry, and solar cells in green energy industry, due to their wide range of tunable band gaps and high carrier mobilities among the III-V compound semiconductors. However, despite the increasing demand in antimonide-based material system for realizing the high performance transistors operated at ultra-low driving voltage (< 0.5 V), the attainment of a high-/(In)GaSb interfaces possessing the low interfacial density of states (Dit) as well as the acceptable thermal stability has yet been achieved. In this dissertation, by depositing the rare-earth oxide, Y2O3, via molecule beam epitaxy (MBE) and atomic layer deposition (ALD), respectively, we have succeeded in passivating the GaSb(100) surface, which forms a thermally stable (> 500 oC) and well-bonded high-/GaSb interface. A detailed comparison between the samples with Y2O3 deposited by MBE and ALD, respectively, has been carried out with respect to the interface chemical bondings and electrical properties. Moreover, dependence of the deposition temperatures of MBE-Y2O3 to the interfacial properties and related MOS device performance has also been discussed. The corresponding chemical bondings and subsequent reactions for the Y2O3/GaSb interface were studied using in situ angle-dependent X-ray photoelectron spectroscopy (XPS). Moreover, the electrical properties for the Y2O3/GaSb interface were studied in terms of the conventional capacitance-voltage (C-V) and leakage current density-electric field (Jg-Eg) characteristics along with the temperature-dependent conductance method (CM) measurements and Gray-Brown (G-B) method analysis for the interfacial density of states (Dit) extraction. Consequently, the self-aligned inversion channel GaSb p-MOSFETs have been fabricated and yielded a record high saturation drain current density (Id,sat) of 130 A/m and maximum transconductance (Gm,max) of 90 S/m. Besides, a low subthreshold slope (S.S.) of 147 mV/decade and a peak field-effect hole mobility (h,FE) of 200 cm2/V-s were also obtained from the GaSb p-MOSFETs with 1 μm-gate-length.