HIPIMS鍍製HfO2氧化層之MIM電容的鐵電量測

Abstract

鐵電材料是目前熱門的研究目標之一，現今科技的發展使得我們對於電子元件的尺寸追求越來越小。然而傳統鐵電材料所鍍製的薄膜厚度大約幾百奈米，薄膜的漏電也非常大，從而影響鐵電材料在記憶體上的應用。所以科學家們開始尋找新型的鐵電材料，並且發現HfO2和ZrO2等材料，有機會取代傳統鐵電材料。其中HfO2更是許多科學家所看好的新型鐵電材料選擇，並嘗試使用不同的鍍製方式來探討HfO2薄膜所能展現出的鐵電特性。 在本研究中，我們將利用高功率脈衝磁控濺鍍 (High Power Impulse Magnetron Sputtering, HIPIMS)來製備HfO2鐵電層。試片的基本結構上為，在P-type矽基板上使用DC sputter鍍製下電極的Mo，再來是鐵電層HfO¬2，最後則是上電極的Al。實驗總共會有三組Sample的變化。Sample 1為在HfO2層中摻雜Zr形成HfO2:Zr薄膜。Sample 2則是在HfO2層上鍍製一層Zr層。Sample 3是在HfO2的上下方分別鍍製TiN層以及ZrN層兩種結構變化。試片完成後，做鐵電性的量測，並配合物性測量作分析。最後，本研究在三組Sample中皆有發現極化現象。在Sample 1中得知HIPIMS鍍製時，氧氣通量在10 sccm表現最佳，並且RTA在850℃時無鐵電性表現。在Sample 2中得知Zr摻雜在HfO2的量不是越多越好，在TEM中看出HIPIMS鍍製時Hf對Mo層造成損害的情況，這情況在Sample 3的結構中能有效的改善。而Sample 3試片的鐵電性在三組中是表現最好的，TiN與ZrN在RTA溫度上的趨勢表現相反，推測是因為兩者在應力結構上表現不同。

關鍵字: 高功率脈衝磁控濺鍍、鐵電材料、二氧化铪

Ferroelectric material is now one of the popular research objectives. Due to the current development of technology, the size of electronic components become smaller and smaller. However, the film thickness of the conventional ferroelectric material is about few hundred nanometers and the current leakage is large, thus effecting the application of ferroelectric material used in memory devices. Therefore, scientists began looking for new ferroelectric materials such as HfO2, ZrO2 and other materials with the opportunity to replace the conventional ferroelectric materials. HfO2 is the choice for many researchers who try to use different deposition methods to find out the ferroelectric properties in HfO2 films. In this research, we used High Power Impulse Magnetron Sputtering (HIPIMS) for the deposition of HfO2 ferroelectric layers. The basic structure of the sample was Al/HfO2/Mo/p-Si which Al and Mo depositing by DC sputter. In Group 1, we doped Zr into HfO2 to form HfO2:Zr layer. In Group 2, we deposited a Zr layer above the HfO2 layer. In Group 3, we formed two different structures in which TiN and ZrN were separately deposited above and at the below HfO2. Then measurements of ferroelectric and physical properties were performed for all the samples.

Keywords: HIPIMS, Ferroelectric material, HfO2