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It has been recently shown that diffusion of dopant during doping of inhomogeneous structure could be accelerated or decelerated in comparison with diffusion of dopant in structure with averaged diffusion coefficient. As a continuation of previous work, the purpose of this paper is to introduce an approach of estimating the limited value of acceleration of the dopant diffusion by choosing the dependence of the dopant diffusion coefficient on the coordinates.

The authors analyzed relaxation of concentration of dopant during diffusion in inhomogeneous material. The authors determine conditions for maximal acceleration and deceleration of diffusion of dopant. The authors introduced analytical approach for analysis of dopant diffusion in inhomogeneous material.

The authors determine conditions for maximal acceleration and deceleration of diffusion of dopant.

It has been shown that dopant diffusion could be decelerated essentially to a greater extent, rather than accelerated.

A new model to describe dopant diffusion and recrystallisation in polycrystalline silicon during thermal treatment is presented. The full 3D microstructure of the material is considered and a local homogenisation approximation introduced. A parallel diffusion model for diffusion in grain boundaries and grain interior with grain growth and segregation is developed within this approximation. The model is solved in a 2D vertical section using a finite element discretisation. An example of the application of this model to a one micron bipolar transistor is given.

The purpose of this paper is to develop a method of preparing spray-on dopant solutions that enable obtaining a p+ region forming a back-surface field (BSF) during the diffusion doping process. The spray-on method used allows to decrease the costs of dopant solution application, which is particularly significant for new low-cost production processes.

This paper presents steps of production of high concentration boron dopant solutions enabling diffusion doping of crystalline p-type silicon surfaces. To check the fabricated dopant solutions for stability and suitability for spray-on application, their viscosity and density were measured in week-long intervals. The dopant solutions described in this paper were used in a series of diffusion doping processes to confirm their suitability for BSF production.

A method of preparing dopant solutions with parameters enabling depositing them on silicon wafers by the spray-on method has been established. Due to hygroscopic properties of the researched dopant solutions, a maximum surrounding atmosphere humidity has been established. The solutions should not be applied by the spray-on method, if this humidity value is exceeded. The conducted derivatographic examination enabled establishing optimal drying conditions.

The paper presents a new composition of a dopant solution which contains high concentration of boron and may be applied by the spray-on method. Derivatographic examination results, as well as equations describing the relation between dopant solution density and viscosity and storage time are also original for this research. The established dependencies between the sheet resistance of the fabricated BSF and the diffusion doping time are other new elements described in the paper.

A simple approach is developed for modelling the distribution of dopant in crystals grown by the Czochralski technique. Allowance is made for the temperature dependence of the diffusivity and for the diffusion of dopant behind the moving boundary. It is found that the effect can make a significant difference to the final dopant distribution. The diffusion process is modelled using a discrete method, previously developed for situations in which the boundary is static.

The purpose of this paper is to analyze the manufacturing of diffusion-junction heterorectifier with account relaxation of mismatch-induced stress. On the basis of the analysis, the authors formulate recommendations to increase sharpness of the p-n-heterojunction, homogeneity of concentration of dopant in the junction and charge carrier mobility.

The authors formulate recommendations to increase sharpness of p-n-heterojunction, homogeneity of concentration of dopant in the junction and charge carrier mobility. To formulate the recommendations, the authors analyzed the manufacturing of the junction. The authors introduce an analytical approach to analyze the manufacturing.

The authors find a possibility to increase sharpness of p-n-heterojunction, homogeneity of concentration of dopant in the junction and charge carrier mobility.

The results are original.

The purpose of this paper is to develop analytical model for gate tunneling current for an ultra‐thin gate oxide n‐channel MOSFET with inevitable nano scale effects (NSE).

A computationally efficient model for gate tunneling current for an ultra‐thin gate oxide n‐channel MOSFET in nano scale is presented. The model predictions are compared with the two‐dimensional Sentaurus device simulation.

Good agreement between the model and experimental data was obtained. The model also shows good agreement when compared with Sentaurus simulation and available model. It is observed that neglecting NSE may lead to large error in the calculated gate tunneling current. The findings provide a guideline to the severity of NSE from the point of view of standby power consumption. It is found that temperature and substrate bias have almost negligible effect on gate tunneling current. The gate tunneling current variation with gate bias, gate oxide thickness and source/drain overlap region have also been assessed.

The present work is concentrated only on the gate leakage current and is useful for gate leakage analysis of the circuits.

The model so developed is conceptually simple, numerically efficient and can be used for circuit simulator.

NSE are considered while modeling the gate tunneling current through nano scale n‐channel MOSFET.

The purpose of this paper is (1) to analyze the dependence of charge carriers mobility in an implanted-junction heterorectifier on mismatch-induced stress and (2) to elaborate an analytical approach for analysis of mass transfer with the possibility to take into account changing of parameters of mass transport in space and time at one time as well as nonlinearity of the considered transfer.

In this paper, the author analyzed charge carriers mobility changing in an implanted-junction heterorectifier under the influence of mismatch-induced stress. The author introduced a model to describe the considered changing of carriers mobility. Based on the analysis of the model, the author formulated conditions (1) to decrease and to increase of the mobility under influence of the stress; and (2) the author analyzed the possibility to control of mismatch-induced stress by radiation processing of materials of the considered multilayer structure. The author also introduced an analytical approach for analysis of mass transfer. The approach gives a possibility to take into account changing of parameters of mass transport in space and time at one time as well as nonlinearity of the considered transfer.

Findings dependence of charge carriers mobility in an implanted-junction heterorectifier on mismatch-induced stress. Also the author finds an analytical approach for analysis of mass transfer. The approach gives a possibility to take into account changing of parameters of mass transport in space and time at one time as well as nonlinearity of the considered transfer.

All results of this paper are original.

The purpose of this study is comparison of the diffusion processes performed using the commercial available dopant paste made by Filmtronics and the original prepared liquid dopant solution. To decrease prices of industrially produced silicon-based solar cells, the new low-cost production processes are necessary. The main components of most popular silicon solar cells are with diffused emitter layer, passivation, anti-reflective layers and metal electrodes. This type of cells is prepared usually using phosphorus oxychloride diffusion source and metal pastes for screen printing. The diffusion process in diffusion furnace with quartz tube is slow, complicated and requires expensive equipment. The alternative for this technology is very fast in-line processing using the belt furnaces as an equipment. This approach requires different dopant sources.

In this work, the diffusion processes were made for two different types of dopant sources. The first one was the commercial available dopant paste from Filmtronics and the second one was the original prepared liquid dopant solution. The investigation was focused on dopant sources fabrication and diffusion processes. The doping solution was made in two stages. In the first stage, a base solution (without dopants) was made: dropwise deionized (DI) water and ethyl alcohol were added to a solution consisting of tetraethoxysilane (TEOS) and 99.8 per cent ethyl alcohol. Next, to the base solution, orthophosphoric acid dissolved in ethyl alcohol was added.

Diffused emitter layers with sheet resistance around 60 Ω/sq were produced on solar grade monocrystalline silicon wafers using two types of dopant sources.

In this work, the diffusion processes were made for two different types of dopant sources. The first one was the commercial available dopant paste from Filmtronics and the second one was the original prepared liquid dopant solution.

We have developed a computer oxidation modeling program, named NOVEL, which has been integrated into our process simulator FINDPRO. It combines the modified Deal‐Grove growth rate model with a nonlinear viscoclastic deformation model to predict both the oxide shape and stress. Modeling the thermal oxidation of silicon presents several numerical challenges. First, the oxide region expands and deforms extensively during the process which has to be modeled as a moving boundary, large deformation problem. Second, the SiO2 mechanical property changes from clastic to viscoclastic to viscous as the processing temperature is changed from a value below the the glass transition temperature (960°C) to one above it. The viscoclastic deformation model which is adequate over the entire temperature range of interest has an intrinsic numerical singularity when the oxide viscosity (divided by time) becomes relatively lower than the elastic modulus at high temperatures. These must be handled appropriately to ensure that the modeled results are correct. In this paper, we present details of how NOVEL solves the above mentioned problems. We show examples of low temperature/high pressure oxidation of a LOCOS structure, trench isolation structure, and the technique by which the finite element program NOVEL interfaces with the finite difference process simulator FINDPRO.

The purpose of this paper is to develop a model that allows determining the boron concentration profile in silicon based on duration and temperature of the diffusion process.

The model was developed on the basis of the Fick’s second law, which is fundamental for describing the diffusion process. The explicit scheme of the finite difference method was used in the conducted simulations. Results of measurements made using the secondary ion mass spectrometry (SIMS) were used as template dopant concentration profiles. Solution of boric acid in ethanol is the dopant source for which this model was developed.

Based on the conducted simulations, it was proposed that besides the influence of electric field of ionized dopants, which is already described in literature, an appropriate factor reflecting the influence of the threshold concentration on the coefficient of diffusion of boron in silicone should also be introduced.

The developed model enables determination of the boron concentration profile in silicon consistent with the results of SIMS measurements. A factor taking into account the influence of threshold concentration on the coefficient of diffusion was introduced. The influence of concentration of boric acid in the dopant solution on the concentration profile was also considered.