不同製程條件的磊晶層對蕭特基二極體電性影響之研究

Study the influence of epitaxial layer with different process conditions on the electrical properties of Schottky diode

藍紹儒(Shao-Ju Lan)

指導教授 ： 陳至信

中原大學/電機資訊學院/電子工程研究所/碩士(2017年)

https://doi.org/10.6840/cycu201700776

摘要

蕭特基二極體(Schottky Diode)的主要缺點是漏電流大與無法在較高的逆向偏壓情況下使用，例如逆向偏壓的額定值最高可到200V，因漏電流值會隨著溫度變化，為避免這樣的變化，蕭特基二極體在逆向偏壓操作時，會比實際額定值小很多。但由於蕭特基二極體的轉換操作速度快，又有極低的雜訊以及起始電壓小的特性，是較接近理想二極體，故應用非常廣泛。
本研究由CVD製程在N型矽基板(111)上成長矽磊晶層，探討在不同磊晶溫度及不同矽磊晶層厚度時，對蕭特基二極體電性的影響，採用二種不同溫度條件，各溫度條件成長三組不同厚度的矽磊晶層薄膜，再以濺鍍機鍍上金屬層，使得金屬層與矽磊晶層間產生P-N接面，利用此接面所具有的獨特特性-蕭特基能障，製作成蕭特基二極體元件，進而針對其結構、電性做量測分析，探討不同溫度製程及不同厚度的矽磊晶層，對元件的逆向偏壓及逆向電流的影響因子。
由結果的探討得知，矽磊晶層薄膜的厚度與成核，是嚴重影響蕭特基二極體特性的因素。改善方法，藉由磊晶製程的控制，減少薄膜成核後，由晶片延伸到磊晶層的疊差、差排、雜質微粒、尖凸物等成膜缺陷，進而改善蕭特基二極體元件的特性。

關鍵字

蕭特基

並列摘要

The main drawbacks of Schottky Diode are the higher leakage current and
the lower operation reverse bias, such as reverse bias spec rating up to 200V
but leakage current variable with the device operation temperature, in order to
avoid leakage current alteration, the operation reverse bias of Schottky diodes
will be much smaller than its reverse bias spec. But Schottky diode is an almost
ideal diode with high switch speed of operation, very low noise and small initial
voltage. There are extensive applications in different fields.
In this study, we use CVD process to epitaxy Si thin film on the N-type Si (111) substrate to investigate the influences of different epitaxial temperature and
different thickness of epitaxial layer for the electrical properties of Schottky diode.
In the process parameters, there are two different substrate temperatures and to
grow three different thickness of Si epitaxial film for each substrate temperature.
Then sputtering the metal film on the Si epitaxial film induces a P-N junction
between the metal film and the Si epitaxial film. By the special Schottky barrier
of this P-N junction, we can produce a Schottky diode device and measure its
structure & electrical properties to analyze the influence parameters of reverse bias
and reverse current in different substrate temperatures and different Si epitaxial thickness.
The results of study discussion show that the thickness and nucleation of the Si epitaxial film are the factors of seriously affecting the characteristics of Schottky
diodes. The improving method is to control the epitaxial layer process and to reduce
the stacking, poor row, impurity particles, sharp objects and other nucleation defects from the wafer extending to the epitaxial layer after the film nucleation. Finally, we
can improve the characteristics of Schottky diode.

並列關鍵字

Schottky

參考文獻

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[17] 薄膜之殘留應力分析

[14] 鍾岑玟, “蕭特基二極體之光罩設計參數最佳化” , 交通大學管理學院碩士論文, 民國一百年十月

[11] 黃建豪, “0.35和0.45微米BCD製程之橫向式蕭特基二極體元件設

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