Quantitative measurement of active dopant density distribution in phosphorus-implanted monocrystalline silicon solar cell using scanning nonlinear dielectric microscopy

Abstract

The performance of silicon (Si) solar cells is dependent on the active dopant distribution in emitters. Estimation of the dopant distribution in a Si solar cell fabricated by ion implantation is difficult due to the pyramidal surface texture of the emitter. Here, we investigate the active dopant distribution in a P-implanted Si solar cell using scanning nonlinear dielectric microscopy (SNDM). SNDM and dC/dz-SNDM are complementarily applied to visualize the carrier distribution in the cross section of the Si solar cell. The carrier density in the emitter is calibrated using the SNDM data obtained from Si standard samples. The results show that the dopant distribution can be described as the sum of two Gaussian functions distributed over the vertical direction of the pyramidal faces. The three-dimensional (3D) dopant distribution is estimated from the superposition of the P distributions at each pyramidal face. The estimated 3D dopant distribution is in good agreement with the SNDM measurement results.

High resolution characterizations of fine structure of semiconductor device and material using scanning nonlinear dielectric microscopy

“…Here, we investigate the active dopant (carrier) distribution in a phosphorus (P)-implanted Si solar cell by SNDM. 30) SNDM (dC=dV ) and dC=dz-SNDM are complementarily applied to visualize the carrier distribution in a cross section of the Si solar cell. The carrier density in the emitter is calibrated using SNDM data taken from standard Si samples.…”

Boxcar Averaging Scanning Nonlinear Dielectric Microscopy

“…As is often done using scanning capacitance microscopy [ 31 ], we can determine the polarity of dominant carriers, p- or n-type, on a local area of a semiconductor from the polarity of the d C /d V signal, and the signal intensity gives local information of carrier concentration with superior sensitivity. If reference samples for calibration can be prepared, the d C /d V imaging can be used for the nanoscale quantitative measurement of non-linear permittivity on dielectrics [ 32 ] and dopant profiling on semiconductors [ 8 , 12 ].…”

“…SNDM was originally devised for imaging electric anisotropy of dielectrics such as ferroelectric domains [ 4 ] and has the potential to become a key technology for ferroelectric probe data storage enabling Tbit/inch 2 recording density [ 5 , 6 ]. The scope of applications has also extended to the nanoscale evaluation of semiconductor materials and devices, including dopant profiling in miniaturized transistors [ 7 , 8 ], imaging the stored charges in flash memories [ 9 ], carrier distribution imaging on SiC power transistors [ 10 ], amorphous and monocrystalline Si solar cells [ 11 , 12 ], and atomically-thin layered semiconductors [ 13 , 14 ]. SNDM and its potentiometric extension can show true atomic resolution in surface dipole imaging on a Si (111)-(7 × 7) surface [ 15 , 16 ] and single-layer graphene on SiC [ 17 ].…”

Microwave Microscopy and Its Applications

“…In practice, one can either apply kilohertz modulation to the gigahertz excitation and demodulate the higher-order signals or directly detect the higher harmonics of the gigahertz signals. By using the former scheme, scanning nonlinear dielectric microscopy has achieved appreciable success in ferroelectrics (129) and semiconductors (130). Similarly, by using a loop probe and the latter scheme, investigators have also detected the nonlinear Meissner response at edges and defects in superconducting samples (131).…”