The Ti/Pt/Au metallization system has an advantage of resisting KOH or TMAH solution etching. To form a good ohmic contact, the Ti/Pt/Au metallization system must be alloyed at 400℃. However, the process temperatures...The Ti/Pt/Au metallization system has an advantage of resisting KOH or TMAH solution etching. To form a good ohmic contact, the Ti/Pt/Au metallization system must be alloyed at 400℃. However, the process temperatures of typical MEMS packaging technologies, such as anodic bonding, glass solder bonding and eutectic bonding, generally exceed 400℃. It is puzzling if the Ti/Pt/Au system is destroyed during the subsequent packaging process. In the present work, the resistance of doped polysilicon resistors contacted by the Ti/Pt/Au metallization system that have undergone different temperatures and time are measured. The experimental results show that the ohmic contacts will be destroyed if heated to 500℃. But if a 20 nm Pt film is sputtered on heavily doped polysilicon and alloyed at 700℃ before sputtering Ti/Pt/Au films, the Pt5 Si2-Ti/Pt/Au metallization system has a higher service temperature of 500℃, which exceeds process temperatures of most typical MEMS packaging technologies.展开更多
Pt rare earth compounds have recently been investigated as potential substitutes.In this study,the hydrogen reduction method was used to prepare the Pt-Dy bimetallic catalyst,and a number of characterizations were con...Pt rare earth compounds have recently been investigated as potential substitutes.In this study,the hydrogen reduction method was used to prepare the Pt-Dy bimetallic catalyst,and a number of characterizations were conducted for structure and morphological research.The high resolutiontransmission electron microscopy(HR-TEM)and X-ray diffraction results show that Pt-Dy composite material exists in the form of various alloys and has a clear spherical shape.The majority of the metals in the composite catalyst appear in the zero valent state,and the binding energy of Pt shifts significantly,according to an X-ray photoelectron spectroscopy measurement.Impressively,Pt-Dy alloy produces excellent mass activity of 594 A/g compared to commercial Pt/C catalyst(162.8 A/g)for oxygen reduction process.Furthermore,after an accele rated durability test,the catalytic activity loss for Pt-Dy alloy catalyst reaches 20%while commercial Pt/C reduces 56%.展开更多
基金supported by the National Natural Science Foundation of China(No.61376114)
文摘The Ti/Pt/Au metallization system has an advantage of resisting KOH or TMAH solution etching. To form a good ohmic contact, the Ti/Pt/Au metallization system must be alloyed at 400℃. However, the process temperatures of typical MEMS packaging technologies, such as anodic bonding, glass solder bonding and eutectic bonding, generally exceed 400℃. It is puzzling if the Ti/Pt/Au system is destroyed during the subsequent packaging process. In the present work, the resistance of doped polysilicon resistors contacted by the Ti/Pt/Au metallization system that have undergone different temperatures and time are measured. The experimental results show that the ohmic contacts will be destroyed if heated to 500℃. But if a 20 nm Pt film is sputtered on heavily doped polysilicon and alloyed at 700℃ before sputtering Ti/Pt/Au films, the Pt5 Si2-Ti/Pt/Au metallization system has a higher service temperature of 500℃, which exceeds process temperatures of most typical MEMS packaging technologies.
基金supported by the National Natural Science Foundation of China(21975151)。
文摘Pt rare earth compounds have recently been investigated as potential substitutes.In this study,the hydrogen reduction method was used to prepare the Pt-Dy bimetallic catalyst,and a number of characterizations were conducted for structure and morphological research.The high resolutiontransmission electron microscopy(HR-TEM)and X-ray diffraction results show that Pt-Dy composite material exists in the form of various alloys and has a clear spherical shape.The majority of the metals in the composite catalyst appear in the zero valent state,and the binding energy of Pt shifts significantly,according to an X-ray photoelectron spectroscopy measurement.Impressively,Pt-Dy alloy produces excellent mass activity of 594 A/g compared to commercial Pt/C catalyst(162.8 A/g)for oxygen reduction process.Furthermore,after an accele rated durability test,the catalytic activity loss for Pt-Dy alloy catalyst reaches 20%while commercial Pt/C reduces 56%.
