Performance Evaluation of Physical Properties on Zinc Sulfide (ZnS)-based Field Effect Transistor

Abstract


A. Introduction
Zinc sulfide (ZnS), a naturally happening salt, is the leading source of zinc.It has two conjoint crystalline forms (polymorphs): Sphalerite ("zinc blende"), by a cubic crystal structure, is the arrangement that preponderates in nature.Wurtzite, by hexagonal crystals, is infrequent, but it can be made by heating system of sphalerite to ≈1020 ºC.ZnS is phosphorescent, which styles it useful for quite a few electronic and decorative applications.Among its prior uses were X-ray and television screens and clock and watch dials.In this stage of development of nanotechnology, ZnS recurrently arrangements the shells of semiconductor quantum dots, with cadmium selenide (CdSe) as the cores [1].
The researcher attempted to accomplish the electrical and electronic properties analyzing of the ZnS-based FET and the other semiconductor devices by applying the computer based simulation approaches and the several experimental processes in relation to the previous literature reviews.Zinc sulfide is utilized for Field Effect Transistor.Because of their highly chemically stable, low solubility, wide band gap, wide transmission range (from visible to IR region) and unique luminescent with electrical and electronic properties.ZnS has received considerable interest over the past few years in the unique nature of broadband gap semiconductors and is considered a potential next-generation highperformance electronics product.Although the perfect ZnS doping has not yet been introduced, it exhibits the greatest electrical carrier flow between oxides and is therefore used in high speed switching devices and certain electronic devices.However, the desire to use ZnS for high-performance electronic devices has not been realized to date, owing to the inherent difficulties of obtaining ZnS and achieving proper doping.Undoped ZnS has n-conductive properties, which are not clear even though some experiments and theoretical studies have been carried out.This is mainly to make p-doping difficult, which is very important for Field Effect Transistor [2].
According to the data from the earlier literature reviews, the p-type layer can select to use as ZnS material, the Mg doped ZnS can be used as n-type layer.The csapphire material can be chosen as a substrate layer because it is supported to achieve the high performance Field Effect Transistor which can be used in power electronics devices.In this work, based on the introduction of band-gap engineering and doping in ZnS, researcher discussed the ZnS-based FETs, comprehensively [3].The band-gap engineering in ZnS is first discussed, which is a very important method to design to design ZnS-based FET.And then, thermal properties can be calculated based on II-VI semiconductor materials before combining the selected materials, electrical and electronic properties too.According to the result, these material can be estimated suitable or not for Field Effect Transistor.Then, the main characteristics such as V-I characteristics and C-V characteristics of the Field Effect Transistor are also determined.Besides, switching rate as function energy for Field Effect Transistor is also estimated to determine the high performance condition.Finally, physical characteristics for Field Effect Transistor are also evaluated because it is the one important point for Field Effect Transistor [4].
The rest of the paper is organized as follows.Section II presents the materials and methods for device modelling and research methodology.Section III mentions the analyses and implementation for numerical analyses.Section IV expresses the results and discussions on the numerical analyses on developed FET structure.Finally, section V concludes the performance evaluation of this study.

B. Research Method
The main aim of this work is to improve the utilization of the semiconductor FET devices.The objectives are (i) to analyze theoretically the electrical properties of semiconductor material (ii) to evaluate the electrical properties of semiconductor materials (ZnS and Si) for JFET (high frequency) device by theoretical approaches [5] (iii) to analyze and simulate I-V characteristics curves of FET devices based on mathematical model [6][7].Figure 1 shows the Proposed ZnS-Based FET Structure.

Substrate
The second step is to model the FET structure based on that materials.The next step is to design the model of the FET based on ZnS material with mathematical equations.The fourth step is to calculate the physical characteristics of FET with output voltage and output current.The next step is to specify the operating region for developed FET by physical applications.The last step is to perform the measurement results and outcomes of the results for targeted FET based on physical parameters with numerical simulation.The performance comparison was done after implementing the experimental studeis.

Analysis and Implementation
The numerical analyses and implementation for considering the physical properties of the developed ZnS-based FET structure have been accomplished by the following mathematical modelling expressions.

Idsat/ID0 Versus VG/VP using the Phenomenological Relationship
It should be reemphasized that the foregoing development, and apply only below pinch-off.In fact, the competed ID versus VD for a given VG actually begins to decrease if VD values in excess of VDsat, are inadvertently substituted.As pointed out in the quantitative discussion, however, ID is approximately constant if VD exceeds VDsat.To first order, then, the postpinch-off portion of the characteristics can be modeled by simply setting The IDsat relationshtp can be simplified somewitat by noting that pinch-off at the drain end of the channel implies W→a when V(L) = VDsat.Therefore, ( ) By comparing the two eauations,

VT Versus NA with x0 as a Parameter (Mathematical Model)
From the qualitative description of FET operation it shunld be obvious that the parameter VT plays a prominent role in determining the precise nature of the device charactermattes.In FET analyses VT is commonly called the threshold or turn-on voltage.The transtutor starts to carry correct (turns on) at the onset of inversion.A compatatioeal expression for the important VT parameter is readily established using the results and the fact that VG = VT when ϕS = 2ϕF.Specifically, given an ideal n-channel (or p-bulk) device, simple suhsritntion yields

Gate Voltage Versus Surface Potential (Mathematical Model)
The gate voltage could be evaluated based on the surface potential for the confirmation of the physical properties of the FET devices. 2

P-Type Deep Depletion FET-C C-V Characteristics (Mathematical Model)
The p-type deep depletion FET-C C-V characteristics is very important parameter for analyzing the mathematical model for targeted FET device in reality.

Depletion Width WT Versus Acceptor and Donor Concentration (Mathematical Model)
The special note should be made of the depletion width, WT, existing at the depletion-inversion transition point.In the delta-depletion formulation, WT is of course the maximum attainable equilibrium depletion width.Since W= WT when ϕs = 2ϕF simple xuhsiitatian into WT yields ( )

VT Versus Temperature (Mathematical Model)
The thermal voltage with respect to temperature is an outstanding parameter for designing the FET devices.

ID Versus VD Characteristics with Square Law (Mathematical Model)
The output characteristics of the FET device could be evaluated based on the square law in microelectronic device theory.The following equations are very important for designing the mathematical model of the developed FET device for real world applications.

ID Versus VD Characteristics with Physical Parameters (Mathematical Model)
The output characteristics of the FET device could be calculated based on the physical parameters in microelectronic device design.The following equations are very significant for designing the mathematical model of the technologically advanced FET device for reality applications.

ID Ratio or Mobility Ratio Versus Temperature (Mathematical Model)
The value of drain current versus temperature is also important for checking the performance of the targeted FET device and the following equations could be utilized for optimized design structure of the FET in fabrication process.

C. Results and Discussions
The proposed model of ZnS FET is given in this study.The result for Idsat/ID0 Versus VG/VP using the Phenomenological Relationship is also initially analyzed to observe the electrical characteristics.And also, the Linear Region for ZnS FET is also mentioned for the electrical characteristics.The Relationship of ID Vs VDS and the Relationship of ID Vs VDS are also analyzed to support to find the electrical characteristics of proposed ZnS FET.The consideration of VT Versus NA with x0 as a Parameter is the main idea for observing the acceptor concentration with junction width for optimum design of ZnS FET.The Gate Voltage Versus Surface Potential result also points out the physical characteristic could depend upon the device structure modelling in high performance condition.The p-Type Deep Depletion FET-C C-V Characteristics is the main idea for junction capacitance variations could be achieved with different voltage level for acquiring the physical characteristics.The results on VT Versus Temperature and Depletion Width WT Versus Acceptor and Donor Concentration highlight the confirmation of theoretical results shall have to be matched with analyses on physical parameters.The ID Versus VD Characteristics with Square Law and normal physical parameters could be found the checking of the optimal characteristics of the ZnS FET.The ID Ratio or Mobility Ratio Versus Temperature directly supports the optimum value of the voltage and current relationship characteristics of ZnS FET.
The value of Idsat/ID0 versus VG/VP using the Phenomenological Relationship is shown in Fig. 3.The variation of Idsat/ID0 depends on the value of VG/VP.Given the difference in functional forms, the agreement is quite good.This result could be support to observe the electrical properties of the proposed FET design.The Relationship of ID Vs VDS is given in Fig. 5.The values of iD and iD ideal and VGS and VGS ideal are increased when the VGS is also increased.This results could also support to calculate the electrical characteristics of FET.The relationship of ID Vs VGS is given in Fig. 6.The VGS can be changed some value in high or some value in low the ID is also changed.This results could also support to calculate the electrical characteristics of FET.The relationship of VT Vs NA with x0 is given in Fig. 7.The VT can be changed all values in high when the NA is also increased with the decreasing value of x0.This results could also support to calculate the voltage and current relationship characteristics of ZnS FET.
The relationship of VG Vs US is given in Fig. 8.The VG shall increase when the surface potential US is also increased.Due to the variation of the surface potential for semiconductor junction, the gate voltage could be robustness of the device performance.This results could also support to calculate the voltage and current relationship characteristics of ZnS FET.The relationship of Depletion Width WT Versus Acceptor and Donor Concentration is given in Fig. 10.The WT can decreased for ZnS materials at room temperature when the NA or ND is also increased from 1×10 14 to 1×10 18 in cm -3 .This results could also support to calculate the voltage and current relationship characteristics of ZnS FET.The relationship of ID Vs VD is given in Fig. 12.The ID can change some value in constant for idea condition or some value in low for square law principle when the VD is increased from 0 V to 10V.This results could also support to the optimum value calculation of the voltage and current relationship characteristics of ZnS FET.

Figure 5 .
Figure 5. Relationship of ID Vs VGS

Figure 6 .
Figure 6.Relationship of ID Vs VGS

Figure 7 .
Figure 7. VT Versus NA with x0 as a Parameter

Figure 9
Figure 9. p-Type Deep Depletion FET-C C-V Characteristics

Figure 10 .
Figure 10.Depletion Width WT Versus Acceptor and Donor

Figure 12 .
Figure 12.ID Versus VD Characteristics with Square Law

Figure 13 .
Figure 13.ID Versus VD Characteristics with Physical Parameters