Enhanced Infrared Absorption Of Si/Si_1-xGe_x Quantum Well APD

In this reaserch,through Silvaco TCAD simulation to design high gain of short-wave near infrared absorption enhanced APD,and add the quantum well structure of APD absorbing area to further improve the long wavelength range of absorption and broaden the scope of APD response.Finally,the purpose of optimizing APD enhanced infrared absorption is achieved.As a first step research using the officer process simulation module design preparation of denotation APD simulation flow sheet,whole process and use the Atlas of APD internal structure can directly set the advantages of simulation to absorb the APD detection.Contrast 12 ?m absorption area APD detection and 10 ?m absorption area for the spectral response of the APD detection,concluded that the absorption peak of10 ?m absorption area SACM structure is 0.5 ?m,and absorb the thickening of the epitaxial layer thickness APD detection has wide spectral response,and in the near infrared region 0.8 ?m 1.1 ?m maintained a larger photocurrent,thus verified the greater absorption area more photons especially long wavelength photon is absorbed in deep absorption device area.Based on more than 10 microns APD devices join Si/Ge heterojunction quantum well structures and its properties photoelectric simulation,got the Ge/Si/Ge heterojunction quantum-well APD photocurrent ahead of dark current 10 V is the result of the breakdown,this means that the light signal amplification dark current when an avalanche multiplication,the noises are restrained effectively.By comparing double heterojunction quantum-well APD and six floors of the Ge quantum well of APD spectrum it is concluded that the increase in the layer number of Ge redshift spectrum peak 0.05 ?m,but the increase in the layer number of Ge heterojunction surface dislocation increases,reducing the carrier transport.Therefore,it is considered to replace the absorption region of the introduced device with Si/Ge heterojunction quantum well with Si/Si1-x Gex quantum well with a smaller mismatch.Through discussion to join with the Ge quantum well structure on the process temperature problems which need to pay attention to design without quantum well in the low temperature of push technology of silicon APD in the control group,and join absorption area Si/Si1-x Gex quantum well structure simulation got the photoelectric properties of them.Si/Si1-x Gex quantum-well APD makes originally the absorption of the silicon avalanche photodiode breakthrough the limitation of the silicon at room temperature cutoff wavelength range effectively widen to 1.2 ?m,at the same time through and not join the quantum well structure are compared,and the spectrum of the control group of Si/Si1-x Gex quantum well structure to absorb area make optical signals in the infrared wave band increased at least 10 times,effectively improve the signal-to-noise ratio.Through the analysis of the Ge content in the x and forbidden band width and the relationship between the refractive index,it is concluded that Si/Si1-x Gex quantum well with the above advantages because Si/Si1-x Gex /Si is not only a quantum well structure or an optical waveguide structure,improve the absorption and utilization of the light.