奈米壓痕技術由於有高負載與位移解析度,以及量測方法之均一性與簡易性等優點,故近年來廣泛被應用於各種類型之材料測試上,應用層面可包含材料之彈性模數,破壞特性與黏彈性質等研究領域.奈米壓痕應用理論,首推Oliver與Pharr所提出之彈性模數轉換模型,而此方式在某些特殊情況下,例如Pile-up導致實際壓痕接觸面積並非理想狀況,以致於硬度與彈性模數計算結果產生差誤,或將奈米壓痕應用於薄膜材料上所產生之基材效應亦會導致此現象.故本文欲探討之目標,不僅侷限於奈米壓痕材料測試範圍,本文並整合其它之測試方法與模擬作為驗證或修正工具,並探討各方法間之相關性.在高分子塊材奈米壓痕研究方面,本文發現了Pile-up效應導致KMPR光阻劑在彈性模數與硬度值求取方面產生差誤,並分別以單軸拉伸與振動測試作為修正工具,而由結果發現了彈性模數之非等向性.在Kalrez AS-568A O-ring rubber奈米壓痕測試上,發現Pile-up現象不明顯,且由單軸壓縮測試之驗證可更確定奈米壓痕應用於此材料之可靠度.在陶瓷薄膜材料研究方面,發現了基材效應影響了PECVD silicon nitride奈米壓痕測試結果,並以以Modified King model與FEM修正基材效應所造成之影響.此外,分別探討了熱處理,使用週期與RTA對此三種材料特性之影響,包含了彈性模數,硬度,黏彈特性,殘留應力與破壞特性等性質.

Nanoindentation technique has been widely used in characterization of mechanical properties of materials at small scales. However, due to some real consideration faced, such as pile-up and substrate effect, during indentation testing, the primary conversion formula proposed by Oliver and Pharr would result in significant errors and it must be modified to compensate these effects. The motivation and goal of this research is therefore in two aspects. First, by characterizing polymers and thin film materials, it is possible to evaluate and quantify the influence of these imperfections during a typical nanoindentation test as the basis toward a more sophisticated conversion model. Second, by characterizing the mechanical properties of novel materials using nanoindentation associated with different processing parameters, it is possible to yield important information for semiconductor and MEMS process optimizations. In order to achieve both goals, a novel polymer photoresist, KMPR, a semiconductor-grade o-ring, and PECVD nitride films, were chosen for this study. For the study on bulk polymeric materials, it was found that the mechanical properties of KMPR and o-ring rubber varied significantly with respect to thermal treatment temperature and the service period, respectively. Furthermore, it could be observed that KMPR specimens have strongly piled-up after nanoindentation. In order to evaluate the pile-up effect, both uniaxial tensile and vibration tests were used for the purposes of comparison and validation. The strong discrepancy between various test results suggested that KMPR is an anisotropic material. On the other hand, the test data obtained from indentation and uniaxial compression for o-ring rubber was highly correlated. By checking the difference in the pile-up extent, it is concluded that the pile-up phenomenon would cause mis-interpretation on the nanoindentation test data. Finally, for the study of thin film materials, it was found that the rapid thermal anealing (RTA) processes could effectively modify the elastic modulus, hardness, and residual stress of PECVD nitride. Fracture and interfacial toughness were also changed after RTA by inspecting the cracks generated during indentation. Moreover, it could also be found that the apparent elastic modulus and hardness were also varied as the penetration depth increased because of the substrate effect. Modified King model and FEM simulation were subsequently performed to compensate the substrate effect. In summary, this study integrated specific testing and simulation methods with nanoindentation for understanding and correcting these non-ideal effects indicated above for different categories of materials. The proposed approach and analyses could also be adopted for testing other similar materials faced in real applications. Finally, by realizing those testing results, structural properties of KMPR after thermal treatment, sealing performance of the o-ring rubber during different service periods, and the structural integrity of PECVD nitride used in semiconductor fabrication, could be obtained. These are important information for structural design optimization to enhance the device longevity and process yield.

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