Microlens arrays have extensive applications on image sensors, optical communications and optical interconnection. In order to analyze the technology of the nanoscale microlens array, it is necessary to analyze the topography of microlens surfaces how to improve the light collection efficiency, increase the pixel fill factor and reduce the optical crosstalk. So we can optimize the technology of the microlens layout and process. SEM imaging technique is a traditional method to study surface structure. However, the probe of SEM does not touch the detected sample surface but the surface is limited to conducting materials. AFM’s probe can touch the sample surface and AFM is suitable to all material surfaces. It is important to adopt the atomic force microscopy (AFM) to investigate the surface topography of microlens array. In this paper, the investigation of nanoscale space microlens array is fabricated on  pixels based on  CMOS imager process. As a result of this study, AFM can provide detailed topographical information about nanoscale space microlens features in terms of the depth, roughness, cross-section of the microlens array compared with SEM. From the microlens surface morphology analysis, verify the nanoscale space microlens array technology to effectively improve the fill factor and reduce the optical crosstalk. Based on  CMOS imager process, the active image sensor is fabricated whose pixel array is  with  nanoscale space microlens. The nanoscale space microlens can obtain the high performance image quality with both brightness and clarity from the output color image.

atomicforcemicroscope, nanoscale space microlens array, topography analysis, fill factor, CMOS active sensors.