由於個人手持式終端產品日漸蓬勃發展，如行動電話、PDA、數位相機與iPod等通訊與消費性產品廣受消費者青睞，影音功能與資料處理運算能力不斷提升，故對記憶體之需求也越來越大。記憶體電路及其應用為提昇記憶體附加價值，並為未來晶片系統的關鍵技術。而嵌入式記憶體佔整個SoC的面積比例較以往大幅提升，顯示了嵌入式記憶體的重要性與日俱增。 本論文提出一個改良型的電流模式感測放大器，並搭配工研院的自旋力矩傳輸型磁阻式記憶體單元，設計出1Kb MRAM的記憶體電路。製程部分主要分為兩段，其前段製程是採用TSMC 0.18 μm 1P6M來實現，而後段製程則是採用ITRI EOL 65 nm搭配實現整體晶片，供應電源為1.8 V及2.5 V。其中，當MTJ在高阻態情況下的阻值為2132 Ω，而在低阻態情況下的阻值為1215 Ω及參考阻態阻值為1512 Ω。提出改良後的電流模式感測放大器可以有效地降低臨界電壓偏移量與提升在預充階段的充電速度，另外也達到降低輸入端偏壓流失率的效果，使感測電路不會因為輸入兩端偏壓值流失太快而影響到感測速度。 經模擬驗證，提出的感測放大器比一般的電流模式感測放大器在速度方面有較好的效能表現，且亦減少了功率延遲積（Power Delay Product ，PDP）的部分，另外也比較了自旋力矩傳輸型磁阻式記憶體單元在阻值上的偏移對感測放大器的影響。According to the rapid evolution of hand-held products, the cell phone、PDA、digital camera and iPOD are more popular with people. The requirements of memory are more than before. The applications of memory circuits are the added value and the key technique for those components. Therefore, the embedded memory is more and more important in SoC. A high-speed current mode sense amplifier for Spin Torque Transfer Magnetoresistive Random Access Memory (STT MRAM) is proposed. The circuit is fabricated by TSMC 0.18 μm 1P6M, the MTJ (Magnetic tunnel junction) utilizes ITRI EOL 65 nm process. The supply voltage are 1.8 V and 2.5 V. The resistance values of high state is 2132 Ω, low state is 1215 Ω, and reference state is 1512 Ω, respectively. The proposed sense amplifier decreases the dropping rate of input bias. In particular, it can reduce the sensing time and the power-delay-product (PDP). The proposed sense amplifier has faster sensing delay than generally current mode sense amplifiers. The reductions of Power-Delay-Product (PDP) are also being. Furthermore, the proposed sense amplifier spends less sensing delay time under various resistances than the others.
