臺灣博碩士論文加值系統

近年來，可攜帶式電子產品被廣泛的使用，諸如數位像機、筆記型電腦、mp3隨身聽、智慧型晶片卡、隨身碟等等的產品，在市場上佔有重要的地位。而這些產品都運用非揮發性記憶體作為儲存資料中心。而非揮發性記憶體又分為： (1)快閃記憶體、(2)SONOS記憶體、(3)奈米點記憶體。SONOS記憶體與奈米點記憶體是近年來研究的重點，這些記憶體都有著低功率損耗與快速的讀寫速度的特性。
由於傳統的快閃記憶體在尺度逐漸縮減下，將面臨儲存資料流失的問題產生，而SONOS記憶體與奈米點記憶體則可以避免這個問題發生。因此在小尺度的記憶體元件製作，SONOS記憶體與奈米點記憶體將是比較好的選擇。
本篇論文將提出一種新的製程方式來形成鍺奈米點。利用兩種靶材一起濺鍍的方式來沉積一層矽-鍺-氧薄膜材料作為儲存載子層。不同於傳統的沉積方式，這是一個新穎的製程方法來成長三層層疊的薄膜。藉著後續的兩種不同熱氧化方式：(1)快速熱氧化、(2)爐管氧化的後段處理之後，將會析出鍺的半導體奈米點。由於不同的兩種氧化時間與氧化溫度，造成不同的實驗結果。我們並提出三種不同的化學反應方程式與能帶圖，試圖用來解釋我們的實驗結果。

In recent years, the portable electronic product have widely applied, such as digit camera, notebook computer, mp3 walkman, intelligent IC card, USB Flash personal disc and so on , these play an important role in the market. These products are all based on nonvolatile memory. Nonvolatile memories include three type: (1)conventional flash memory, (2)SONOS memory, (3)nanocrystal memory. These memories have low power losing and fast program/erase speed.
Flash memory has leaking and program/erase problems when scaling down, but SONOS and nanocrystal memory have not these problems. Therefore, in the process of scaling down memory device, SONOS and nanocrystal memory are the better choice.
In this thesis, we will bring up a new idea of crystallize nanocrystal. Co-sputter system has been introduced to deposit a SizGeyOz film to replace the Floating Gate in Flash structure. Unlike the conventional process, this is a new process to deposit tri-layer of memory structure, and SixGeyOz is a new material. After two different thermal treatments è RTO and Furance, Ge in the SizGeyOz film will be segregated to crystallize Ge nanodots embedded in the SiO2/GeOx film. There are three situations in RTO and Furnace oxidation because the different duration and temperature of oxidation, Three energy band models and chemical formulas can be considered to support experiment results.

Chinese Abstract　---------------------------------------- i
English Abstract　-------------------------------------- iii
Acknowledgment　 ---------------------------------------- v
Contents　 -------------------------------------- vii
Figure Captions　 ----------------------------------------ix
Chapter 1 Introduction
1.1 General Background　 -------------------------- 1
1.2 SONOS nonvolatile memory device -------------- 4
1.3 Nanocrystal nonvolatile memory device -------- 5
1.4 Motivation -----------------------------------10
1.5 Organization of the dissertation　-------------12
Chapter 2 Basic principles of nanocrystal memory
2.1 Introduction　--------------------------------- 13
2.2 The principle of the threshold voltage shift--- 13
2.3 Basic operation principles ------------------- 14
Chapter 3 Experimental process to form germanium nanocrystal by Co-sputter system and thermal treatment
3.1 Experimental sample preparation　-------------- 16
3.2 Result and discussion　------------------------ 18
3.3 Conclusion ----------------------------------- 18
Chapter 4 Result and discussion of experimental samples after thermal treatment ( RTO and Furnace )
4.1 Introduction　--------------------------------- 19
4.2 Furnace oxidation 800℃ 30min ------------------ 19
4.3 RTO ( RTA + O2 ) 600℃ 60sec and 900℃ 60sec -- 21
Chapter 5 Conclusions --------------------- 33

References　-----------------------------------------35

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Chapter 4:
[4.1] H.G. CHEW1, W.K. CHOI1,2, Y.L. FOO3, W.K. CHIM1,2, E.A. FITZGERALD1,4, F. ZHENG2,S.K. SAMANTA2, Z.J. VOON2 , K.C. SEOW2 “TEM study on the evolution of Ge nanocrystals in Si oxide matrix as a function of Ge concentration and the Si reduction process” , J. Appl. Phys.
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