scholarly journals Quinhydrone Chemical Passivation of a Silicon Surface for Minority Carrier Bulk-Lifetime Measurements

2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
M. Solcansky ◽  
J. Vanek ◽  
A. Poruba

For the measurement of the minority carrier bulk-lifetime the characterization method MW-PCD is used, where the result of measurement is the effective carrier lifetime, which is very dependent on the surface recombination velocity and therefore on the quality of a silicon surface passivation. This work deals with an examination of a different solution types for the chemical passivation of a silicon surface. Various solutions are tested on silicon wafers for their consequent comparison. The main purpose is to find optimal solution, which suits the requirements of a time stability and start-up velocity of passivation, reproducibility of the measurements and a possibility of a perfect cleaning of a passivating solution remains from a silicon surface, so that the parameters of a measured silicon wafer will not worsen and there will not be any contamination of the other wafers series in the production after a repetitive return of the measured wafer into the production process. The cleaning process itself is also a subject of a development.

2014 ◽  
Vol 16 (39) ◽  
pp. 21804-21811 ◽  
Author(s):  
Vandana Vandana ◽  
Neha Batra ◽  
Jhuma Gope ◽  
Rajbir Singh ◽  
Jagannath Panigrahi ◽  
...  

Silicon surface passivation is studied using Al2O3 films by the thermal ALD process. A surface recombination velocity of below 10 cm s−1 is realized for short annealing times (∼100 s). As-deposited and annealed films show the presence of positive fixed charges.


2005 ◽  
Vol 108-109 ◽  
pp. 585-590 ◽  
Author(s):  
Olivier Palais ◽  
Mustapha Lemiti ◽  
Jean-Francois Lelievre ◽  
Santo Martinuzzi

In this work the efficiencies of different surface passivation techniques are compared. This paper emphasizes on the passivation provided by SiNx:H layers that is commonly used in photovolaic industry as surface passivation and anti reflection layer. The method used to evaluate the surface recombination velocity is detailed and discussed. It is shown that light phosphorus diffusion at 850°C – 20 min provides good surface passivation of n-type silicon surface and noticeable passivation of p-type, that can be improved by SiNx:H Layer.


2005 ◽  
Vol 891 ◽  
Author(s):  
Zhimei Zhu ◽  
Elena Plis ◽  
Abdenour Amtout ◽  
Pallab Bhattacharya ◽  
Sanjay Krishna

ABSTRACTThe effect of ammonium sulfide passivation on InAs/GaSb superlattice infrared detectors was investigated using two complementary techniques, namely, picosecond excitation correlation (PEC) measurement and variable-area diode array (VADA) surface recombination velocity (SRV) measurement. PEC measurements were conducted on etched InAs/GaSb superlattice mesas, which were passivated in aqueous ammonium sulfide solutions of various strengths for several durations. The PEC signal's decay time constant (DTC) is proportional to carrier lifetimes. At 77 K the PEC signal's DTC of the as-grown InAs/GaSb superlattice sample was 2.0 ns, while that of the unpassivated etched sample was reduced to 1.2 ns by the surface states at the mesa sidewalls. The most effective ammonium sulfide passivation process increased the PEC signal's DTC to 10.4 ns. However it is difficult to isolate surface recombination from other processes that contribute to the lifetime using the PEC data, therefore a VADA SRV measurement was undertaken to determine the effect of passivation on surface recombination. The obtained SRV in the depletion region of the InAs/GaSb superlattice and GaSb junction was 1.1×106 cm/s for the unpassivated sample and 4.6×105 cm/s for the passivated sample. At 77 K the highest R0A value measured in our passivated devices was 2540 W cm2 versus 0.22 W cm2 for the unpassivated diodes. The results of the lifetime, the SRV and the R0A measurements indicate that ammonium sulfide passivation will improve the performance of InAs/GaSb superlattice infrared detectors.


1970 ◽  
Vol 17 (2) ◽  
pp. 119-124 ◽  
Author(s):  
Karolis GULBINAS ◽  
Vytautas GRIVICKAS ◽  
Haniyeh P. MAHABADI ◽  
Muhammad USMAN ◽  
Anders HALLÉN

n- and p-type 4H-SiC epilayers were grown on heavily doped SiC substrates. The thickness of the p-type layer was 7 µm and the doping level around 1017 cm 3, while the n-type epilayers were 15 µm thick and had a doping concentration of 3 - 5*1015 cm 3. Several different surface treatments were then applied on the epilayers for surface passivation: SiO2 growth, Al2O3 deposited by atomic layer deposition, and Ar-ion implantation. Using collinear pump - probe technique the effective carrier lifetimes were measured from various places and statistical lifetime distributions were obtained. For surface recombination evaluation, two models are presented. One states that surface recombination velocity (SRV) is equal on both the passivation/epi layer interface (S2) and the deeper interface between the epilayer and the SiC substrate i. e. (S1 = S2). The other model is simulated assuming that SRV in the epilayer/substrate (S1) interface is constant while in the passivation layer/epilayer (S2) interface SRV can be varied S2 < S1. Empirical nomograms are presented with various parameters sets to evaluate S2 values. We found that on the investigated 4H-SiC surfaces S2 ranges from 3x104 to 5x104 assuming that the bulk lifetime is 4 (µs. In Ar+ implanted surfaces S2 is between (105 - 106) cm/s.http://dx.doi.org/10.5755/j01.ms.17.2.479


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