# Structure and Technological Parameters’ Effect on MISFET-Based Hydrogen Sensors’ Characteristics

^{*}

## Abstract

**:**

_{2}O

_{5}-SiO

_{2}-Si structure. In the calculations, the parameters of the models obtained on the basis of the previous experimental results were used. It was shown how STPs and their technological variations, taking into account the electrical parameters, can affect the characteristics of MISFET-based hydrogen sensors. It is noted, in particular, that for MISFET with submicron two-layer gate insulators, the key influencing parameters are their type and thickness. Proposed approaches and compact refined models can be used to predict performances of MISFET-based gas analysis devices and micro-systems.

## 1. Introduction

_{2}interfaces of MIS sensors. MIS sensors with different gate material (palladium [6], platinum and iridium [7]), with dielectric films SiO

_{2}, Si

_{3}N

_{4}-SiO

_{2}, TiO

_{2}-SiO

_{2}and Ta

_{2}O

_{5}-SiO

_{2}have been investigated [8]. The semiconductors Si [4,7], GaAs [3,9] and SiC [10] were used in MIS gas sensors to detect the low concentrations of gases H

_{2}[6], NH

_{3}[7], H

_{2}S [11], NO

_{2}[12] and CO [13]. The studies have shown that performance characteristics of MISFET-based hydrogen sensors depend on technological parameters [8], electrical modes [14], chip temperature [15] and external factors (e.g., irradiation [16]).

_{x}H

_{y}and PdO compounds are formed in palladium films, and the films themselves can swell and peel off from the substrate [17]. These effects lead to irreversible and/or reversible changes in the electrical conductivity of the films and the work of the electron output from Pd [3], which is the physical principle of operation of some types of hydrogen sensors.

_{x}H

_{y}compounds, the concentration, structure and “lifetime” of which strongly depend on the chip temperature and hydrogen concentration [14]. Some hydrogen atoms penetrate to the boundary, with the dielectric either directly through the pores in the palladium film or via the tunnel mechanism through palladium grains (clusters) [5,11]. It is these atoms that form a polarized dipole layer of H in the Pd–insulator interface [6]. In work [20], based on modeling, doubts are expressed about the possibility of forming a dipole layer at the palladium–dielectric boundary. Third, there may be diffusion and drift protons in the insulator [21].

_{2}[12,31]). Note that sensor developments [13,26] are based on functionalized Single-Walled Carbon Nanotubes (SWNTs).

_{2}-Si, Pd/Ti-SiO

_{2}-Si, Pd (or Pt)-Ta

_{2}O

_{5}-SiO

_{2}-Si structures. Experiments have demonstrated that MISFETs have the best performances compared to MIS capacitors and resistors. In addition, the integrated sensors, containing MISFET with a Pd(Ag)-Ta

_{2}O

_{5}-SiO

_{2}-Si-structure (hereinafter referred to as TSE), possess the best stability and reproducibility of characteristics [21]. In recent years, we have investigated the metrological and operating characteristics of TSE (e.g., electrical modes [14], chip temperature [15] and irradiation [16]).

## 2. Materials and Methods

#### 2.1. Initial Structure and Technological Parameters of TSE

_{0}, a and b of the TSE characteristic electrophysical models.

_{3}is (12 ± 0.2), w is (3.2 ± 0.02) mm, L is (10 ± 0.1) μm, µ

_{n}is (200 ± 5) cm

^{2}/(V∙s), N

_{A}is (5 ± 0.02) × 10

^{15}cm

^{−3}, then the relative errors of the parameters C

_{0}, a and b are equal to 3.5%, 4.5% and 8.7%, respectively.

_{k}∈ {p

_{k}} (k = 1, 2, …, 13 in Table 2). In general, the absolute and relative errors of the parameters Δp

_{k}and δp

_{k}are equal to ׀p

_{kn}− p

_{k}׀ and (Δp

_{k}/p

_{kn}) × 100%, respectively. The value of p

_{kn}is the desired (nominal) value of parameter p

_{k}or its average value, if this parameter was determined experimentally from a set of measured values.

_{k}depend on the film manufacturing technologies (for parameters with indices k ∈ {1; 2; 3; 4; 5; 6}, on photolithography technologies (for p

_{8}, p

_{9}), on methods of estimating their thicknesses (for parameters with indices k ∈ {4; 5; 6} and on the type and structure of the materials (for parameters with indexes k ∈ {11; 12; 13}. Typically, the values of Δw and ΔL are in the range of 0.1 to 0.5 microns, and values Δd ∈ [5 nm; 15 nm] depend on d. The relative errors δw and δL are in the range from 0.002%...0.01% to 1.1%...5%. For specific technologies of the semiconductor wafers and dielectric films production, the relative errors δε

_{1}, δε

_{2}, δε

_{3}, δµ

_{n}and δN

_{A}usually do not exceed 2%. The relative errors of δd

_{1}and δd

_{2}are in the range of δd

_{min}∈ [2%; 10%] to d

_{max}∈ [7.5%; 30%] and are the maximum for the STPs. Consequently, the thicknesses d

_{1}and d

_{2}, the dimension of which will be determined in nm, can be considered the most critical STP.

#### 2.2. Metrological Characteristics of TSE

_{d}and integral S sensitivities being equal to dV/dC and ΔV/ΔC; absolute ΔC and relative δC errors of measurement C; the sensitivity threshold C

_{th}; minimum relative error δC

_{min}; the boundaries of the working range C

_{1}and C

_{2}, limited by a given error δC

_{max}and finally C

_{max}.

_{0}− ΔV(C)], where the initial value of V (at C = 0) is equal to V

_{0}. In general, the output signals V of MISFETs-based sensors are formed as a result of the embedding of one or more transistors in various measurement circuits. In this paper, the main components of the models are determined using experimental studies of one TSE in the mode with a constant current I

_{D}and the voltage V

_{D}as shown in Figure 2b. In this case,

_{G}(C) = V

_{G}

_{0}− ΔV

_{G}(C) and S

_{d}= dV

_{G}/dC,

_{G}

_{0}(φ

_{s}) = φ

_{s}+ a·{φ

_{s}+ φ

_{T}·exp[(φ

_{s}− 2φ

_{s}

_{0})/φ

_{T})]}

^{1/2}+ φ

_{ms}

_{0}− [Q

_{te}

_{0}+ Q

_{ss}(φ

_{s})]/C

_{0}.

_{G}(C) = ΔQ

_{te}(C)/C

_{0}− Δφ

_{ms}(C) = ΔV

_{m}· [1 − exp(−k

_{C}·C)] > 0.

_{d}is equal to [−k

_{C}·ΔV

_{m}· exp(−k

_{C}·C)]. The maximum relative error of measuring the gas concentration δC in the general case is represented as

**|**S

_{d}

**|**+ ΔV + Δ(V)]/(C

**|**S

_{d}

**|**),

_{G}) is the absolute voltage error associated with an absolute error of the parameter p

_{k}and is approximately equal to [dV

_{G}/dp

_{k}]·Δp

_{k}. Then, after sensor calibration the sensitivity threshold C

_{th}is (ΔV/

**|**S

_{dmax}

**|**), minimum relative error is δC

_{min}and the boundaries of the working range C

_{1}and C

_{2}can be determined as solutions of Equations (5) and (6). The value of δC

_{min}is δC (at C is C

**), where C**

^{*}**is the solution of the following equation:**

^{*}_{1}and C

_{2}are solutions of Equation (6) with respect to C at a given δC

_{max}greater than δC

_{min}:

_{max}= 100% × [Δ(C)

**|**S

_{d}

**|**+ ΔV + Δ(V)]/(C

**|**S

_{d}

**|**),

_{max}= (1/k

_{C}) · ln (ΔV

_{m}/ΔV).

_{2}O

_{5}-SiO

_{2}-Si structure was fabricated on a single chip (2 × 2 mm

^{2}) together with a (p–n) junction temperature sensor and heater resistor by means of conventional n-MOS technology. Technological processes are detailed and presented in [14,21].

## 3. Results

#### 3.1. Influence of Film Manufacturing Technology and Thicknesses on the Components of the Conversion Function

_{m}can affect the conversion function components ΔQ

_{te}(C) and Δφ

_{ms}(C). In the investigated TSE Pd film (d

_{m}is 70 ± 5 nm) was prepared using laser evaporation in vacuum 2·10

^{−3}Pa in the substrate’s temperature range of 300–400 °C. For this technology, at thicknesses d

_{m}that is less than 80 nm, the palladium film has a porous structure. Therefore, it can be assumed that the hydrogen sensitivity and response time will be independent of d

_{m}and of its deviations Δd

_{m}from the nominal values of d

_{mn}. For other technologies (for example, with thicknesses of nanostructured Pd films less than 30 nm), the response time decreased, and the sensitivity can be increased at low concentrations (~5–50 ppm) with a decrease in d

_{m}[32]. Quantitative analysis of the effect of the Pd films’ characteristics on the hydrogen sensitivity of the TSE requires special experimental studies, which have not been observed in this work.

_{1}and d

_{2}can affect the conversion function components V

_{G}

_{0}and ΔV

_{m}, which according to (2) and (3) are inversely proportional to specific capacity C

_{0}:

_{G}

_{0}= φ

_{s}+ 0.085 + {41·[φ

_{s}+ 0.033·exp((φ

_{s}− 0.42)/0.033)]

^{1/2}− 5}/C

_{0}(V),

_{m}= ΔQ

_{tem}/C

_{0}− Δφ

_{msm}= 15/C

_{0}+ 0.11 (V),

_{0}= (ε

_{0}ε

_{1}ε

_{2})/(ε

_{1}d

_{2}+ ε

_{2}d

_{1}),

^{2}, capacitance is nF/cm

^{2}and thicknesses is nm. With an increase in the hydrogen concentration, the work of the electron output from Pd decreases, and therefore you have a negative value Δφ

_{ms}(C) [3]. The absolute ΔC

_{0}and relative δC

_{0}being equal to 100% × ΔC

_{0}/ΔC

_{0}errors for C

_{0}are, respectively, equal to:

_{0}= ε

_{0}[ε

_{2}d

_{1}(Δε

_{1}·ε

_{2}+ 2Δε

_{2}·ε

_{1}) + ε

_{1}d

_{2}(Δε

_{2}·ε

_{1}+ 2Δε

_{1}·ε

_{2}) + ε

_{1}·ε

_{2}(Δd

_{2}·ε

_{1}+ Δd

_{1}·ε

_{2})]/(ε

_{1}d

_{2}+ ε

_{2}d

_{1})

^{2},

_{0}= [δε

_{1}(2ε

_{1}d

_{2}+ ε

_{2}d

_{1}) + δε

_{2}(2ε

_{2}d

_{1}+ ε

_{1}d

_{2}) + δd

_{2}·ε

_{1}d

_{2}+ δd

_{1}·ε

_{2}d

_{1}]/(ε

_{1}d

_{2}+ ε

_{2}d

_{1}),

_{1}, Δε

_{2}, Δd

_{1}and Δd

_{2}and δε

_{1}, δε

_{2}, δd

_{1}and δd

_{2}are the absolute and relative errors of the corresponding values. For the values, ε

_{1}is 25 and ε

_{2}is 4, and the dependences of the components C

_{0}and δC

_{0}on thicknesses of d

_{2}at different values of d

_{1}are shown in Figure 3.

_{i}. For example, when creating a SiO

_{2}film via silicon oxidation in dry oxygen, the dependence of d

_{2}(t) for various Tp is shown in Figure 4 (based on Figure 8a in [32]). At the initial stage of silicon oxidation (up to d

_{2}is about 30 nm), the thickness of the SiO

_{2}film is proportional to the oxidation time t; with further oxidation, the thickness of d

_{2}is proportional to (t)

^{1/2}. If the oxidation of silicon in dry oxygen is carried out at a temperature of 1100 °C, then the thickness d

_{2}is v

_{1}·t (nm) at t ∈ [0; 10 min] and d

_{2}= 30 + v

_{2}·(t)

^{1/2}(nm) when the t is greater than 10 min, where v

_{1}and v

_{2}are equal to 4.0 nm/min and 8.5 nm·min

^{½}; [t] is min.

_{2}is (δv

_{2}+ 100% × Δt/t) or δd

_{2}is (δv

_{2}+ 50% × Δt/(t)

^{1/2}), where δv

_{2}depends on the dispersion of the plate temperature ΔTp. The value of Δt is determined by the time parameters of the temperature response Tp (t) when the plate is introduced into the core with the constant temperature and partial pressure of oxygen, or by the time parameters of establishing a constant partial pressure of oxygen after oxygen is introduced into the placement zone of the plate heated to the operating temperature Tp and the time of oxygen pressure drop. Usually, δv

_{2}< 0.5% and Δt ∈ (0.5; 2) min. For a given thickness d

_{2}, the error δd

_{2}can be estimated as δd

_{2}being less than the value of [0.5% + 425Δt/(d

_{2}− 30)]. For example, if d

_{2}is 50 nm and Δt is 30 s, then the value of δd

_{2}< 11.1%, and if d

_{2}is 80 nm and Δt is 30 s, then the value of δd

_{2}< 4.75%.

_{0}, which can be considered a key parameter affecting the TSE conversion function.

#### 3.2. Influence of Material’s Parameters and Topological Dimensions of Elements on Conversion Function Components

_{3}, N

_{A}, µ

_{n}) and topological dimensions (L, w) affect parameters a and b, which depend on the value of C

_{0}. According to (2), the conversion function component V

_{G}

_{0}depends on the variables parameters a and φ

_{s}. Then, the absolute error ΔV

_{G}

_{0}with small deviations Δa and Δφ

_{s}a from their average values can be presented as:

_{G}

_{0}= (∂V

_{G}

_{0}/∂φ

_{s})Δφ

_{s}+ (∂V

_{G}

_{0 /}∂a)Δa = 0.01·(K

_{φ}·φ

_{s}·δφ

_{s}+ K

_{a}·a·δa),

_{φ}= 1+ 0.5a(1+ exp m)/(φ

_{s}+ φ

_{T}·exp m)

^{1/2}; K

_{a}= (φ

_{s}+ φ

_{T}·exp m)

^{1/2}; m = (φ

_{s}− 2φ

_{s}

_{0})/φ

_{T}.

_{3}, N

_{A}and C

_{0}, and the potential φ

_{s}depends on the given values of I

_{D}and V

_{D}. According to the simplified TSE electrical model [15], the dependence I

_{D}(V

_{G}) at φ

_{s}> 2φ

_{s}

_{0}has two sections: parabolic when I

_{D}∈ [I

_{D}

_{0}; I

_{D}

_{1}] and φ

_{s}∈ [2φ

_{s}

_{0}; φ

_{s}

_{1}], and linear when value of I

_{D}is greater than I

_{D}

_{1}being equal to (I

_{D}

_{0}+ 0.5bV

_{D}

^{2}). In principle, the entire range of changes in the drain current I

_{D}and gate voltage V

_{G}corresponding to the inversion mode can be used to measure the hydrogen concentration. Usually, the values of the set current are within the error range: I

_{D}is I

_{Dn}± ΔI

_{D}.

_{s}> φ

_{s}

_{1}) is chosen, in which the measurement errors ΔV

_{G}

_{0}and δC are minimal. For example, when V

_{D}is 0.2 V (I

_{D}

_{1}is 42 μA) and I

_{D}is equal to (20 ± 2) μA, the value of V

_{G}

_{0}is (1.16 ± 0.01) V, and when I

_{D}is equal to (100 ± 2) μA, the value of V

_{G}

_{0}is (1.25 ± 0.005) V. Then, the values of I

_{D}and fluctuations of Δφ

_{s}are represented as:

_{D}= b·{a·V

_{D}·[(φ

_{s}+ φ

_{T}exp m)

^{1/2}− φ

_{s}

^{1/2}] − 0.5V

_{D}

^{2}}; Δφ

_{s}≈ 2ΔI

_{D}·(φ

_{s}+ φ

_{T}exp m)

^{1/2}/[a·b·V

_{D}·(1 + exp m)].

_{s}on the current I

_{D}at different V

_{D}and on values of V

_{G}

_{0}at different C

_{0}are shown in Figure 5. The relative errors of conversion function components a and b are equal to:

_{0}+ 0.5(δε

_{3}+ δN

_{A}) = 4.5% and δb = δC

_{0}+ δµ

_{n}+ δw + δL = 8.7%.

_{0}and (w/L) are presented in Table 3. As an example, Figure 5 shows the coordinates of the points corresponding to the values V

_{G}

_{0}being equal to 1.2 V, 1.4 V and 1.7 V for different V

_{D}and a given drain current of 1 mA.

#### 3.3. Influence of Specific Capacity on the Main Metrological Characteristics of TSE

_{0}are presented in Figure 6 and in Table 4.

## 4. Discussion

- All the considered STPs of the TSE (p
_{k}in Table 2) affect the components of the conversion function on which the main metrological characteristics depend. - The deposition technology and thickness of the metal film dm can affect the conversion function components ΔQ
_{te}(C) and Δφ_{ms}(C) on which the sensor’s hydrogen sensitivity and the response time depend. A quantitative analysis of the effect of the Pd films technological characteristics on TSE hydrogen sensitivity requires special experimental studies. In the investigated TSE, the Pd film has a porous structure. Therefore, it can be assumed that the hydrogen sensitivity and response time will be independent of d_{m}and of its deviations Δd_{m}from the nominal values of d_{mn}. - The values of V
_{G}_{0}and ΔV_{G}_{0}depend on N_{A}, C_{0}and the given electrical parameters I_{D}and V_{D}. With the growth of I_{D}and V_{D}, the error ΔV_{G}_{0}decreases. As a result of the calibration of the measuring device, the zero error is determined by the error ΔV_{G}_{0}or the instrumental error of the voltage measurement ΔV (in the examples considered, ΔV is 1 mV).

## 5. Conclusions

_{2}O

_{5}-SiO

_{2}-Si structure, manufactured according to a specific technology, a quantitative assessment of the effect of STPs on the initial value of the output signal, hydrogen sensitivity, absolute and relative errors in measuring gas concentration, the sensitivity threshold and the hydrogen concentration range for a given maximum relative error is given. The calculations used engineering physical models obtained on the basis of selected electrophysical and electrical models.

## Author Contributions

## Funding

## Institutional Review Board Statement

## Informed Consent Statement

## Data Availability Statement

## Conflicts of Interest

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**Figure 1.**The structure and the schematic designation of TSE: 1 is gas-sensitive film, 2 is metal gate, 3 and 9 are drain and source contacts, 4 and 8 are passivating films, 5 and 10 are drain and source, 6 is substrate, 7 is channel, 11 is thin gate dielectric.

**Figure 2.**(

**a**) The input informative parameter is the gas concentration C; the output informative parameter is the voltage of the output signal V; the operating chip temperature is T; the parameters of the electrical mode of the circuit are the current I

_{D}and the voltage V

_{D}; external influencing factors {Z

_{j}} are molecules of other gases, temperature, humidity and radiation background of the environment. (

**b**) The circuit for measuring the dependence V as function of C.

**Figure 3.**(

**a**,

**b**) are dependences C

_{0}(d

_{2}) and δC

_{0}(d

_{2}) at d

_{1}: 1 → 0 nm; 2 → 40 nm; 3 → 80 nm; 4 →120 nm.

**Figure 4.**Dependence of the SiO

_{2}film thickness d

_{2}on the oxidation time t in dry oxygen at temperatures: 1 → 900 °C; 2 → 1000 °C; 3 → 1100 °C; 4 → 1200 °C.

**Figure 5.**Dependences of values φ

_{s}on the current I

_{D}at different V

_{D}(1→ 0.1 V; 2 → 0.2 V; 3 → 0.3 V), and on values of V

_{G}

_{0}at different C

_{0}(1→ 30 nF/cm

^{2}; 2 → 40 nF/cm

^{2}0.2 V; 3 → 50 nF/cm

^{2}).

**Figure 6.**Dependence of δC(C) for different C

_{0}: 1 → 30 nF/cm

^{2}; 2 → 40 nF/cm

^{2}; 3 → 50 nF/cm

^{2}. The values of C

_{1}and C

_{2}correspond to the square points on the curves. The color indicates the working area for the curve corresponding to the capacity of 50 nF/cm

^{2}.

Symbols | Parameters | Values |
---|---|---|

Parameters of semiconductor and dielectric materials | ||

ε_{1}, ε_{2} and ε_{3} | relative permittivity of Ta_{2}O_{5}, SiO_{2} and Si | 25, 4 and 12 |

N_{A} | concentration of acceptors in Si | 5 × 10^{15} cm^{−3} |

µ_{n} | electron mobility in the channel | 200 cm^{2}/(V∙s) |

Dimensions of structural elements | ||

L and w | channel length and width | 10 μm and 3.2 mm |

d_{1} and d_{2} | thicknesses of Ta_{2}O_{5} and SiO_{2} | 90 nm and 80 nm |

d_{m} | thickness of the gate metal film | 70 nm |

Constants and derived parameters | ||

ε_{0} | dielectric constant of vacuum | 8.85 × 10^{−12} F/m |

k | Boltzmann constant | 1.38 × 10^{−23} J/K |

q | electron charge | 1.6 × 10^{−19} Cl |

d | thickness of the gate dielectric is (d_{1} + d_{2}) | 170 nm |

ε | effective permittivity of the dielectric layer is (dε_{1}ε_{2})/(ε_{1}d_{2} + ε_{2}d_{1}) | 7.1 |

C_{0} | specific capacity of the dielectric (ε_{0}ε)/d | 37 nF/cm^{2} |

a | charge parameter in Si is (2q ε_{0}∙ε_{3}∙N_{A})^{1/2}/C_{0} | 1.18 V^{1/2} |

b | specific steepness is (µ_{n}w C_{0})/L | 2 mA/V^{2} |

Physical and electrical parameters | ||

φ_{ms} | output work difference potential Pd– Si | φ_{ms}_{0} = 85 mV |

T | chip temperature | 400 K |

φ_{T} | thermal potential (kT/q) at 400 K | 33 mV |

φ_{gb} | the potential of the band gap in Si | 1.08 V |

φ_{s}_{0} | the potential of acceptors’ level is φ_{T} ln(N_{A}/n_{i}) at 400 K | 0.21 V |

φ_{s} | surface potential is [φ(SiO_{2} − Si) − φ_{F}] | 0.2…0.8 V |

Q_{te} and Q_{ss} | charge densities in the dielectric and in SiO_{2} − Si interface | (5…100) nKl/cm^{2} |

I_{D} | drain current | (2…300) μA |

V_{D} | voltage between the drain and the source | (0.1…0.5) V |

V_{G} | voltage between the gate and the substrate | (1…3) V |

Q_{te} and Q_{ss} | charge densities in the dielectric and in SiO_{2} − Si interface | (5…100) nCl/cm^{2} |

I_{D} | drain current | (2…300) μA |

V_{D} | voltage between the drain and the source | (0.1…0.5) V |

V_{G} | voltage between the gate and the substrate | (1…3) V |

k | STP | Components of TSE Models | |
---|---|---|---|

1 | film production technologies | Pd | ΔQ_{te} (C); Δφ_{ms}(C); φ_{ms0} |

2 | Ta_{2}O_{5} | ΔQ_{te}(C); C_{0}; b | |

3 | SiO_{2} | Q_{te0}; Q_{ss}; C_{0}; b | |

4 | film thicknesses | Pd (d_{M}) | ΔQ_{te} (C); Δφ_{ms}(C) |

5 | Ta_{2}O_{5} (d_{1}) | ΔQ_{te}(C); Q_{te0}; C_{0}; b | |

6 | SiO_{2} (d_{2}) | Q_{te0}; C_{0}; b | |

7 | acceptor concentration | (N_{A}) | a; φ_{s0}; Q_{ss} |

8 | channel length | (L) | b |

9 | channel width | (w) | |

10 | electron mobility in the channel | (µ_{n}) | |

11 | relative dielectric permittivity | Ta_{2}O_{5} (ε_{1}) | a; b; C_{0} |

12 | SiO_{2} (ε_{2}) | ||

13 | Si (ε_{3}) |

**Table 3.**Average values of parameters for different C

_{0}and (w/L) at I

_{D}is 0.1 mA and V

_{D}is 0.2 V.

Parameters → | δC_{0},% | a, V | δa, % | w/L Is 0.003 | w/L Is 0.006 | ||||
---|---|---|---|---|---|---|---|---|---|

↓ C_{0}, nF/cm^{2} | b, mA/V^{2} | δb, % | ΔV_{G}_{0}, mV | b, mA/V^{2} | δb, % | ΔV_{G}_{0}, mV | |||

30 | 2.1 | 1.37 | 3.1 | 1.62 | 7.3 | 6 | 3.24 | 7.0 | 3 |

40 | 3.6 | 1.02 | 4.6 | 2.16 | 8.8 | 4.6 | 4.32 | 8.5 | 2.3 |

50 | 5.5 | 0.82 | 6.5 | 2.70 | 10.4 | 3.7 | 5.4 | 10.1 | 1.8 |

**Table 4.**Average values of metrological characteristics for different C

_{0}at δC

_{max}being equal to 7%.

MC → | V_{G}_{0},V | ΔV_{m},V | k_{C},1/(vol.%) | S_{dmax},V/(vol.%) | δC_{min},% | C_{th},ppm | C_{1},ppm | C_{2},ppm | C_{max},ppm |
---|---|---|---|---|---|---|---|---|---|

↓ C_{0}, nF/cm^{2} | |||||||||

30 | 1.55 | 0.61 | 8 | 4.88 | 4.9 | 2.0 | 50 | 1410 | 8016 |

40 | 1.52 | 0.42 | 3.36 | 5.5 | 2.9 | 90 | 1210 | 7550 | |

50 | 1.48 | 0.32 | 2.56 | 6.1 | 3.9 | 160 | 960 | 7210 |

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## Share and Cite

**MDPI and ACS Style**

Podlepetsky, B.; Samotaev, N.; Etrekova, M.; Litvinov, A. Structure and Technological Parameters’ Effect on MISFET-Based Hydrogen Sensors’ Characteristics. *Sensors* **2023**, *23*, 3273.
https://doi.org/10.3390/s23063273

**AMA Style**

Podlepetsky B, Samotaev N, Etrekova M, Litvinov A. Structure and Technological Parameters’ Effect on MISFET-Based Hydrogen Sensors’ Characteristics. *Sensors*. 2023; 23(6):3273.
https://doi.org/10.3390/s23063273

**Chicago/Turabian Style**

Podlepetsky, Boris, Nikolay Samotaev, Maya Etrekova, and Artur Litvinov. 2023. "Structure and Technological Parameters’ Effect on MISFET-Based Hydrogen Sensors’ Characteristics" *Sensors* 23, no. 6: 3273.
https://doi.org/10.3390/s23063273