臺灣博碩士論文加值系統

後金屬退火製程長期以來一直被用來作為降低金屬-氧化物-半導(簡稱金氧半)體元件介面陷阱密度的一個有效方法。金氧半元件的可靠度可以經由在氫氣、氫與氮的混合氣體(forming gas)、氨氣、一氧化氮或一氧化二氮的環境中進行後金屬退火處理來獲得改善。最近文獻中報導，利用同位素的效應，使用氘氣(D2)後金屬退火可以有效的減輕金氧半元件熱載子效應，它比目前製程中所常用的氮氣或氫氣的退火處理對MOS元件可靠度提升的效果還明顯。
雖然文獻中有關氘氣後金屬退火處理的報告非常多，大多數卻都侷限於金氧半場效應電晶體(MOSFET)可靠度的改善，而且幾乎沒有人探討不同氘氣後金屬退火條件對MOSFET可靠度的影響。因此本論特別對經過不同氘氣後金屬退火條件處理之金氧半電容(MOSC)的可靠度特性進行研究。
在本論文中，我們改變了施加於MOSC上之氘氣後金屬退火條件，包括使用不同的退火溫度、不同的D2/N2的流量比及不同的退火時間，我們針對這些MOSC量測其在經過電應力作用前後之電流-電壓(I-V)特性、高-低頻電容-電壓(Hi-Lo CV)特性、介面陷阱密度及平帶電壓。在本論文中，我們所使用的電應力包括了不同極性的定電流應力(constant current stress)及定電壓應力(constant voltage stress)。為了比較起見，我們也對經過氫氣及forming gas後金屬退火處理之MOSC進行研究。
我們發現經過D2 PMA處理後後之MOSC與氫氣或氮氣之退火處理比較，確實展現了較佳的抗電應力的特性。我們也發現在進行氘氣後金屬退火處理時，較高的氘氣流量、較長的退火時間及較高的退火溫度可以使樣品呈現較佳的抗電應力的特性。
因此，由我們實驗的結果顯示，對於鋁閘極之金氧半元件施以氘氣後金屬退火處理，可以改善元件之抗電應力的特性。

Post-metallization-anneal (PMA) has long been used as an effective way to reduce the interface trap density in metal-oxide-semiconductor (MOS) devices. The reliability of MOS devices can be improved by performing post-metallization-anneal in H2, in mixture of H2 and N2 (forming gas), in NH3, in NO or N2O environment. Deuterium post-metallization-anneal (D2 PMA) has recently been reported to be able to alleviate the hot-carrier effect in metal-oxide-semiconductor field-effect-transistor (MOSFET) due to its isotope effect.
Even through many reports concerning D2 PMA can be found in the literature, most of them mainly aimed at the reliability improvement in MOSFETs and few of them discussed the effects of different D2 PMA conditions on the reliability. Therefore, in this thesis, we studied the reliability property of MOS capacitor subjected to different D2 PMA conditions.
In our study, we changed the D2 PMA conditions applied to MOS capacitors, such as using different annealing temperature, different D2/N2 flow ratio and different annealing time, and investigated the current-voltage (I-V) characteristics, the high-low capacitance-voltage (Hi-Lo CV) characteristics, the interface trap density and the flat-band shifts before and after electrical stress. Both the constant current stress and constant voltage stress with different polarities were used in this work. In order to make a comparison, MOS capacitors subjected to H2 PMA and forming gas PMA were also studied.
We found that by applying D2 PMA does make MOS capacitors exhibit better resistance to electrical stress when compared with those capacitors subjected to N2 or H2 PMA. We also found that higher D2 flow rate, longer PMA time and higher annealing temperature make samples exhibit better characteristics under electrical stress.
Therefore, from our experimental data, we conclude that D2 PMA is beneficiary to the resistance to electrical stress characteristics of Al-gate MOS devices.

第O章 論文架構-----------------------------------------------1
第一章 簡介
1-1 研究動機------------------------------------------------3
1-2 MOS元件歷史回顧-----------------------------------------5
1-3 MOS元件目前的進展---------------------------------------6
第二章 小尺寸金氧半元件與刀氣後金屬退火技術
2-1 MOS元件所面臨的問題------------------------------------7
2-2 氘氣後金屬退火製程簡介---------------------------------9
2-2-1 簡 介-------------------------------------------------9
2-2-2 氘氣後金屬退火製程原理-------------------------------10
第三章 樣品備製與實驗
3-1 樣品備製----------------------------------------------11
3-2 實驗流程簡介------------------------------------------12
3-3 退火的過程及條件的選擇--------------------------------13
3-4 量測系統簡介------------------------------------------14
3-4-1 C-V量測系統簡介-------------------------------------14
3-4-2 I-V量測系統簡介-------------------------------------14
第四章 量測結果與討論
4-1 Stress條件與量測參數設定-------------------------------15
4-2 典型氘氣退火樣品之特性與Stress效應---------------------17
4-3 不同氘氣流量的影響-------------------------------------18
4-4 不同退火溫度的影響-------------------------------------21
4-5 不同退火時間的影響-------------------------------------24
4-6 氘氣與傳統後金屬退火處理之影響-------------------------26
4-7 Charge to Breakdown 與 Weibull plot--------------------29
第五章 結論與未來工作
5-1 結論-----------------------------------------------------30
5-2 未來工作-------------------------------------------------33
參考文獻------------------------------------------------------97

【1】I.C. Kizilyalli, J.W. Lyding, K. Hess “Deuterium Post-Metal Annealing of MOSFET for Improved Hot Carrier Reliability” IEEE Electron Device Letters, vol.18, No.3, March 1997.
【2】Karl Hess, I.C. Kizilyalli, J.W. Lyding”Giant Isotope Effect in Hot Electron Degradation of Metal Oxide Silicon Devices”IEEE Transactions on Electrons, vol.45, No.2, February 1998.
【3】Zhi Chen, Kangguo Cheng, Jinju Lee, Joseph W. Lyding, Karl Hess, Sundar Chetlur, “Deuterium Isotope Effect for AC and DC Hot-Carrier Degradation of MOS Transistors: A Comparison Study”IEEE Transactions on Electron Devices, vol.48, No.4, April 2001.
【4】W.F. Clark, T.G. Ference, T.B. Hook, K.M. Watson, S. W. Mittl, J. S. Burnham”Process Stability of Deuterium-Annealed MOSFET ”, IEEE Electron Device Letters, vol.20, No.1, January 1999.
【5】Kangguo Cheng, Karl Hess, Joseph W. Lyding”Deuterium Passivation of Interface Traps in MOS Devices”, IEEE Electron Device Letters, vol.22, No.9, September 2001.
【6】Zhi Chen, Karl Hess, Jinju Lee, Joseph W. Lyding, Elyse Rosenbaum, Isik Kizilyalli, Sundar Chetlur, ”Mechanism for Hot-Carrier-Induced Interface Trap Generation in MOS Transistors”, IEDM-99 , p.85-88
【7】2001 IEEE EDS Vanguard Seriers of Independent Short Courses
【8】Robert F. Pierret “Semiconductor Device Fundamentals”
【9】Dieter K. Schroder”Semiconductor Material and Device Characterization”
【10】NDL Short Course “Symposium on Nano Device Technology 2001”
【12】Kithley Instruments, Inc. “Model 82-WIN Simultaneous C-V Measurement User Manual “.
【13】D.A. Neamen,”Semiconductor Physics & Devices”.
【14】J. Maserijian and N. Zamani “Behavior of the Si/SiO2 Interface Observed by Foeler-Norheim Tunneling “ J. Appl. Phys. , vol.53, p.559, 1982.
【15】K.F. Schuegraf, D. Park , and C.Hu, “Reliability of Thin SiO at Direct-Tunneling Voltages”, in Int. Electron Devices Meeting Tech Dig. ,1994, p.609 .
【16】Kangguo Cheng, Karl Hess, Joseph W. Lyding, “Deuterium Passivation of Interface Traps in MOS Devices”, IEEE Electron Device Letters, Vol. 22, No. 9, September 2001.