摘要
发展了一种与CMOS工艺完全兼容并可在商业化的1.2μm标准CMOS生产流水线上进行流片的硅基热电堆真空传感器的制造技术与流程。传感器为悬浮的多层复合薄膜结构,其上制作了n型多晶硅加热器和20对由p型多晶硅条和铝条构成的热电堆。利用标准制造工艺中铝层图形的掩蔽作用,使用干法刻蚀工艺一方面去除了传感器表面的SiNx层,使复合介质薄膜减至三层介质,即场氧化层、硼磷硅玻璃和层间介质,从而提高了传感器响应率;另一方面去除了传感器区域内腐蚀孔中的多层介质,将其中的硅衬底裸露,以便完成后续的四甲基氢氧化铵(TMAH)体硅各向异性腐蚀工艺,使传感器成为悬浮绝热结构,这种工艺具备铝保护性能,因此腐蚀中无需任何掩模。最终得到的器件尺寸为124μm×100μm,在空气压强为0.1 Pa^105Pa之间的响应电压为26 mV^50 mV,响应时间为0.9 ms^1.3 ms。这种器件的制造技术具有工艺简单、成品率高、成本低、重复性好等特点。
A silicon-based thermopile vacuum sensor was designed and fabricated. The fabrication technology and process of a silicon-based thermopile vacuum sensor were described. The process was CMOS compatible and can be completed in commercial 1.2 μm standard CMOS process line followed by maskless anisotropic wet etching of silicon substrate. The device was a multi-layer micro- bridge suspended over an etched recess on silicon substrate, with a polysilicon heater and 20 polysilicon-aluminum thermocouples on it. When heated by polysilicon heater, the temperature of the bridge will increase and vary with vacuum degree. This variation of temperature can be measured by thermopile. The following contents were described： 1. The structural design of the device, 2. Fabrication process, 3. Analysis and test results. The result shows that with special design of device structure and fabrication process, the commercial standardCMOS process line can satisfy the production of the device such as vacuum sensor. Device with acceptable performance can be achieved.
出处
《微细加工技术》
EI
2008年第2期23-27,32,共6页
Microfabrication Technology
