- 學位論文
HfSiON閘極氧化層成份對nMOSFET之熱載子效應
Hot Carrier Effects on nMOSFETs Having Different Compositions of HfSiON Gate Dielectrics
摘要
45 nm世代以下，高介電係數(high-κ)閘極介電層的使用是必然的趨勢， HfSiON則是最有可能的選擇之一，因為相較其他的high-κ材料，它有較高的熱穩定性以及較高的遷移率。但是HfSiON的品質和可靠性，仍然是令人擔憂的問題。 本研究中，我們測試的nMOSFET元件，來自聯電的90 nm製程，其具有不同成份的HfSiON(Hf:Si=3:1、1:1、1:3)閘極介電層，我們利用這些晶片，進行熱載子之應力測試，藉由量測I-V、C-V、及charge pumping等性能曲線，來分析研究其劣化之特性。 由研究結果發現，不論是CHC或是DAHC，高溫時之電流衰退程度比低溫嚴重；另外，當HfSiON介電層的濃度比例在Hf:Si=1:3時，其試片呈現出較好的HC可靠度。而濃度比例為Hf:Si=3:1時，其試片呈現出較差的HC可靠度。
並列摘要
Below 45 nm generation, it is necessary to use high-κ gate dielectrics. The HfSiON is one of the most promising candidates because of its high thermal stability and high inversion layer mobility comparing to other gate dielectrics. But the quality and reliability of HfSiON, were still concerned by the people in the field. In this research, the tested nMOSFETs were from 90 nm technology of UMC. The devices have gate stacks structure where HfSiON has different compositions (Hf : Si = 3 : 1, 1 : 1 and 1 : 3). These wafers were used to implement stress. Before and after stress, the characteristics of the these transistors measured by I-V、C-V、and charge pumping methods. From the results of the measurements, high temperature cases generate more degradation than low temperature cases in either CHC or DAHC stress modes. In addition, the nMOSFETs show better HC reliability at Hf : Si = 1 : 3 and worse at Hf : Si = 3 : 1.