材料分析Part C 微區成份分析簡介

前面提過，材料的性質由組成元素、晶體結構、和顯微結構決定。在B篇章節內介紹一些常用的微奈米影像分析，用於分析材料與元件的顯微結構。本篇將簡介一些常用的微區成份分析技術，包含AES，XPS，SIMS等表面分析儀，和能量散佈能譜儀(EDS)，以及電子能量損失能譜儀(EELS)。

We mentioned that properties of a material depend on its composition, crystal structure, and microstructure. Some image analysis techniques for nano materials and nano devices had been discussed in paragraph B. This paragraph will discuss some routinely used techniques for composition analyses, including AES, XPS, SIMS, EDS, and EELS.

許多材料的研發過程中，會經過熱處理的過程，某些新相會在熱處理過程中產生。這些新相的成份和晶體結構通常需要經過材料分析技術的鑑定，此時成份分析就不可避免的要進行。半導體元件是經過設計的結構，在嚴謹控制的製程條件下，一層一層長上去的。所以正常狀況下，從影像就可以知道半導體元件各層的組成，通常無需進行成份分析。唯有在某些新製程或新配方的研發階段，以及異常點的分析，才需要進行成份分析。半導體元件材料分析有一個特殊的領域叫做逆向工程分析，說白一點就是偷看別人的產品設計。逆向工程的材料分析時，由於結構不是自家的，所以影像分析和成份分析都需要。

Heat treatment is usually used in R&D of many new materials, some new phases are formed during the heating process. The composition and crystal structure of these new phases needs to be identified by techniques of materials analysis. Composition analyses are necessary in this field. On the other way, semiconductor devices are designed and manufactured by carefully controlled processes. The composition of each layer is known from images, and composition analysis is usually not necessary. In semiconductor industry, composition analysis is only wanted in R&D of new recipes and in failure analysis. One special field in materials analysis for semiconductors is reverse engineering. It is to spy on other’s products honestly. Because the target is unknown, composition analysis as well as image analysis are required.

鑑定週期表上的元素，可經由原子質量，或者經由原子內電子特定的鍵結能階，如圖C-1。因此，分析組成元素的儀器分成二大類型：質譜儀和能譜儀。對於固態材料分析領域，成份分析儀器以能譜儀居多，如EDS、EELS、AES、XPS、…等等，而SIMS則是固態材料分析領域，唯一比較常用的質譜儀。

We can identify elements in the periodic table by their mass or the characteristic bonding energy of electrons in atoms. Thus, spectroscopes are divided into two groups: mass spectroscopes and energy spectroscopes. For solid state materials, most spectroscopes are energy type, such as EDS, EELS, AES, XPS, … etc., SIMS is the only one mass spectroscope routinely used. 

圖C-1 週期表內元素的鑑定。