以白金為銅之擴散阻障層製作全面銅金屬化之磷化銦異質接面雙極電晶體及其特性量測

Abstract

本論文係利用白金作為擴散阻障層成功的製作出全面銅金屬化之磷化銦異質接面雙極電晶體。此電晶體之N型與P型歐姆接觸分別為Ti/Pt/Cu和Pt/Ti/Pt/Cu，連接線金屬為Ti/Pt/Cu，其擴散阻障層為白金。由歐傑縱深分析、X光繞射分析、原子力顯微鏡及片電阻量測之結果，評估Pt在n+-InGaAs/Ti/Pt/Cu/Cr及GaAs/Ti/Pt/Cu/Cr兩多層結構中，在350oC 30分鐘退火後，均為有效的擴散阻障層。將元件施以24小時，電流密度80 kA/cm2之電流加速測試，其電流增益在高壓電流測試後並沒有下降。另外，將元件施以200oC，1小時與3小時的熱處理，元件特性並沒有太大的改變。我們證明以白金為擴散阻障層，Ti/Pt/Cu及Pt/Ti/Pt/Cu為歐姆接觸金屬，可成功的製作出全面銅金屬化的磷化銦異質接面雙極電晶體。

The fully Cu metallization InP heterojunction bipolar transistor (HBT) using Platinum (Pt) as diffusion barrier has been successfully fabricated and demonstrated in this study. The InP HBT uses Ti/Pt/Cu for n-type, Pt/Ti/Pt/Cu for p-type ohmic contacts metals and Ti/Pt/Cu for interconnect metals with Pt as the diffusion barrier. Both the n+-InGaAs/Ti/Pt/Cu/Cr multilayer structure and GaAs/SiNx/Ti/Pt/Cu/Cr structure were stable up to 350oC 30 min annealing as judged from data of AES, XRD, and AFM and from the measurement of the sheet resistance. Current accelerated stress test was conducted on the device with current density (JC) of 80 kA/cm2 for 24 hours, the current gain showed no degradation after the high current stress. The devices were also thermally annealed at 200oC for 1 and 3 hours and showed no dramatic changes. Overall, we have successfully demonstrated that fully Cu metallization InP HBT can be achieved by using Pt as the diffusion barrier and Ti/Pt/Cu and Pt/Ti/Pt/Cu as the ohmic contacts.