Microwave Cutoff Research Articles

Effect of probe structure on wave transmission spectra of microwave cutoff probe

Effect of probe structure on wave transmission spectra of microwave cutoff probe

Transmission spectrum analysis of ceramic-shielded microwave cutoff probes in low-pressure plasmas

Transmission spectrum analysis of ceramic-shielded microwave cutoff probes in low-pressure plasmas

ZnPc based multifunctional devices designed as fast capacitors, rectifiers, infrared detectors and microwave resonators adequate for 6 G technology applications

Herein Zinc phthalocyanine (ZnPc) based multifunctional devices are fabricated and characterized. The device fabrication included formation of an Au nanosheets onto n-Si wafers and coating these nanosheets with 500 nm thick ZnPc layer. Silver and platinum were used to form a Schottky and an ohmic contacts with n-Si and ZnPc, respectively. The device hybrid structure (Ag/n-Si/Au/p-ZnPc/Pt; abbreviated as ASZ) is composed of Ag/n-Si Schottky arm and p- and n- layers forming pn junction separated by Au nanosheets. Electrical and photoelectrical measurements on the ASZ devices have shown their ability to perform as conventional metal-oxide-semiconductor capacitors (CMOS). These CMOS devices showed light and frequency controlled charge accumulation, depletion and inversion mechanisms within the range of 1.0–50 MHz. The flat band and threshold voltages of the ASZ capacitors are engineered by the imposed ac signal frequency and by infrared (IR) light. In addition, ASZ devices performed as biasing controlled IR photosensors and as current rectifiers. A rectification ratio of 103, IR light sensitivity of 39, specific detectivity of .96 ×109 Jones and current responsivity exceeding 9.0 mA W−1 are recorded at biasing voltage of 4.5 V. Moreover ASZ devices displayed microwave resonator characteristics presented by negative capacitance effect, resonance –antiresonance phenomena and high microwave cutoff frequency. The latter is larger than 10 GHz nominating the device for 6 G technology applications.

Experimental validation of particle-in-cell/Monte Carlo collisions simulations in low-pressure neon capacitively coupled plasmas

Plasma simulations are powerful tools for understanding fundamental plasma science phenomena and for process optimisation in applications. To ensure their quantitative accuracy, they must be validated against experiments. In this work, such an experimental validation is performed for a one dimensional in space and three dimensional in velocity space particle-in-cell simulation complemented with the Monte Carlo treatment of collision processes of a capacitively coupled radio frequency plasma driven at 13.56 MHz and operated in neon gas. In a geometrically symmetric reactor the electron density in the discharge centre and the spatio-temporal distribution of the electron impact excitation rate from the ground into the Ne 2p1 level are measured by a microwave cutoff probe and phase resolved optical emission spectroscopy, respectively. The measurements are conducted for electrode gaps between 50 mm and 90 mm, neutral gas pressures between 20 mTorr and 50 mTorr, and peak-to-peak values of the driving voltage waveform between 250 V and 650 V. Simulations are performed under identical discharge conditions. In the simulations, various combinations of surface coefficients characterising the interactions of electrons and heavy particles with the anodised aluminium electrode surfaces are adopted. We find, that the simulations using a constant effective heavy particle induced secondary electron (SE) emission coefficient of 0.3 and a realistic electron–surface interaction model (which considers energy-dependent and material specific elastic and inelastic electron reflection, as well as the emission of true SEs from the surface) yield results which are in good quantitative agreement with the experimental data.

Analysis of the transmission spectrum of the microwave cutoff probe influenced by the sheath around the probe

We investigated the effect of the sheath around the probe tips on the transmission spectrum of a cutoff probe using an electromagnetic simulation and a circuit model. Our results show that the width of the sheath can change the transmission spectrum, which can affect the absolute value of the electron density. In a real-world cutoff probe structure, this effect may become apparent in a low-density plasma or when a high bias voltage is applied to the plasma. The key factor is capacitance, which contains the sheath component. In the case of a low-density plasma, the change in the sheath capacitance of the sheath region contributes to the shift in the resonant frequency. For thick sheath widths, at least a 5% discrepancy can occur between the actual plasma frequency and the measurement owing to variations in the capacitance, particularly the sheath components surrounding the probe. We expect that this study will facilitate reduction in the measurement error and uncertainty in microwave cutoff probe measurements, particularly when applied to low-density plasma measurements.

Lead-tungsten oxide interfaces designed as gigahertz/terahertz filters

Herein amorphous tungsten oxide thin films of thicknesses of 300 nm are coated onto semitransparent Pb films (100 nm) by the thermal evaporation technique under a vacuum pressure of 10−5 mbar. Optical investigations in these films have shown that Pb nanosheets enhances the light absorbability in the visible and infrared ranges of light without significant change in the energy band gap value. In addition deep analyses of the optical conductivity and terahertz cutoff frequency spectra of the Pb/WO3 optical filters revealed that the cutoff frequency value in the visible range of light is invariant with light signal energy indicating the possibly of filtering none-monochromatic light signals. On the other hand imposing an ac signal between the terminals of Pb/WO3/Au devices has proofed the ability of the device to perform as low pass and as band stop filters workable in the microwave frequency domain. The microwave cutoff frequency for this device reached ∼9 GHz nominating it for use in 5 G mobile technology. The current study showed that coating of tungsten oxide onto semitransparent Pb substrate and coverage small area of the top contact with Au can allow functioning the device as gigahertz/terahertz band filters suitable for communication technology.

Yb/Se/WO3/Yb Thin Film Transistors as Rectifiers, N‐Channel Metal Oxide Semiconductor Capacitors, Laser Sensors, and Microwave Bandstop Filters

Herein, Yb/p–Se/p–WO3/Yb heterojunctions are employed as multifunctional devices. The devices which show back‐to‐back Schottky (BBS) diode characteristics are prepared by the thermal evaporation method under a vacuum pressure of 10−5 mbar. The structural and morphological analyses on these heterojunctions have shown the growth of amorphous WO3 onto meshed nano/microwire network of hexagonal selenium. The BBS diodes display voltage‐controlled current rectification ratios. In addition, the domination of the thermionic and tunneling current conduction mechanisms in the transistors is computationally investigated. Moreover, studies of the capacitance–voltage characteristic curves demonstrate the performance of the devices as n‐channel metal oxide semiconductor (NMOS) field‐effect transistors responsive in the frequency domain of 1.0–50.0 MHz. Furthermore, the impedance spectroscopy measurements in the frequency domain of 0.01–1.80 GHz indicate the possibility of using the BBS diodes as bandstop filters. The microwave cutoff frequency of these filters reaches 1.06 GHz. On the other hand, when ohmic contacts are formed on the glass/Se/WO3 part using two carbon electrodes, the active layer between the electrodes displays high sensitivity to light irradiations from He–Ne lasers, indicating the possibility of performing as photosensors.

Yb/WO3/Yb back to back Schottky barriers designed as voltage controlled rectifiers and as microwave resonators

Herein, 𝑝 −WO3 thin films coated onto ytterbium thin film substrates are used as active layers to fabricate a back to back Schottky (BBS) barriers. The Schottky contacts and the tungsten oxide active layers are grown by the thermal evaporation technique under a vacuum pressure of 10-5 mbar. The films are structurally, morphologically, optically and electrically characterized. The physical nature of the grown 𝑝 −WO3 layers is amorphous comprising excess oxygen in its composition. Electrically, the BBS devices displayed a biasing dependent current rectification ratio confirming the tunneling type of Schottky barriers. The current conduction are dominated through tunneling barriers of height of ~0.80 eV. The barriers allow hole tunneling within energy barriers of widths of ~45 nm and of 300 nm under reverse and forward biasing conditions, respectively. In addition, the impedance spectroscopy measurements have shown the ability of wide tunability of the resistance and capacitance of the devices resulting in a microwave cutoff frequency exceeding 2.0 GHz. The resistive and capacitive features of the devices in addition to the microwave cutoff frequency spectra nominate the Yb/𝑝-WO3/Yb BBS devices for use as microwave resonators suitable for 4G/5G technologies.

Yb/WO3/Ga2S3/Au multifunctional electronic hybrid devices fabricated as tunneling diodes, MOSFETS, microwave resonators and 5G band pass/reject filters

Herein, Tungsten trioxide-gallium sulfide heterojunctions which are prepared by the thermal evaporation technique under a vacuum pressure of 10-5 mbar are employed as active media to fabricate a multifunctional device. The WO3/Ga2S3 (WG) heterojunctions which are deposited onto Yb substrates and top contacted with Au pads of areas of 1.5× 10 −2 cm2 displayed electronic hybrid device structure composed of two Schottky arms connected to a 𝑝𝑛 junction. The constructed Yb/WG/Au devices showed tunneling diode characteristics with current conduction dominated by thermionic emission and quantum mechanical tunneling. In additions, the capacitance-voltage characteristic curves indicated the formation of PMOS and NMOS under reverse and forwards biasing conditions demonstrating a metal oxide semiconductor fields effect (MOSFET) transistor characteristics. Moreover, the impedance spectroscopy tests on the devices have shown that the device can perform as tunable microwave resonator suitable for 5G technologies. The resonator showed frequency based capacitance tunability and displayed microwave band pass/reject filter characteristics. The microwave cutoff frequency of the Yb/WG/Au band filters reaches 9.65 GHz with voltage standing wave ratios of 1.06 and return loss factor of ~29 dB.

Effect of lanthanum substrates on the structural, optical and electrical properties of copper selenide thin films designed for 5G technologies

In this work, copper selenide thin films coated onto glass and transparent lanthanum substrates are studied. The (glass, La)/CuSe thin films which are prepared by the thermal evaporation technique under a vacuum pressure of 10−5 mbar are structurally, morphologically, optically, dielectrically and electrically characterized. Lanthanum substrates improved the crystallinity by increasing the crystallite size and decreasing both of the microstrains and defect density of copper selenide. La substrates redshifts the energy band gap and doubled the dielectric constant values. In addition, employing Drude–Lorentz approaches for optical conduction to fit the dielectric constant provided information about the effects of La substrates on the drift mobility, plasmon frequency, free carrier density and scattering times at femtosecond level. The drift mobility increased and the plasmon frequency range is modified when La substrates are used. Verifying impedance spectroscopy tests in the microwave frequency domain have shown the ability of the La(gate)/CuSe/Ag (source) transistors performing as band pass filters. These filters are suitable for 5G technologies. The microwave cutoff frequency reached ~ 5.0 GHz at a notch frequency of 2.80 GHz of the glass/La/CuSe/Ag highpass filters.

Au/CdBr2/SiO2/Au Straddling‐Type Heterojunctions Designed as Microwave Multiband Pass Filters, Negative Capacitance Transistors, and Current Rectifiers

Herein, SiO2 nanosheets with thicknesses of 25−100 nm are used to enhance the performance of Au/CdBr2 Schottky barriers. The Au/CdBr2/SiO2/Au straddling‐type heterojunction devices are prepared by the thermal evaporation technique. It is observed that SiO2 layers enhance the crystallinity of CdBr2 through increasing the crystallite sizes and decreasing the defect density, stacking faults, and microstrain by 50%, 56%, 32%, and 34%, respectively. A work function of 6.38 eV is determined from the temperature‐dependent electrical resistivity measurements of type CdBr2. In addition, it is observed that, when coated with 50 nm‐thick SiO2, the Au/CdBr2/SiO2/Au straddling‐type transistors can reveal high current rectification ratios of 6.9 × 102 at low biasing voltages in the range of 0.06−0.30 V. The alternating current signals’ analysis in the microwave range of spectra indicates that the current conduction mechanism is dominated by the correlated barrier hopping and quantum mechanical tunneling. It is observed that the Au/CdBr2/SiO2/Au devices exhibit a negative effect accompanied with resonance−antiresonance in the capacitance spectra. Moreover, the microwave cutoff frequency which reaches ≈165.1 GHz and the magnitude of reflection coefficient spectra show that the device under study can perform as multiband pass/stop filters suitable for wire/wireless communication applications including 3G/4G technologies.

Yb/InSe/SiO₂/Au Straddling-Type Tunneling Devices Designed As Photosensors, MOS Capacitors, and Gigahertz Bandstop Filters

In this work, amorphous InSe thin films coated with 30-160-nm-thick SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> are used as an active material to fabricate multifunctional devices. The n-InSe/p-SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> layers that are deposited onto ytterbium substrates are optically and electrically characterized. It was observed that the coating of SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> nanosheets onto the surface of InSe enhances the light absorbability in the near-infrared range without remarkable altering of the bandgap. Significant increase in the steady-state photocurrent values accompanied by faster photocurrent responses resulted from the coating of SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> nanosheets. Electrically, while the Yb/InSe/Au channels display tunneling Schottky barrier characteristics, the Yb/InSe/SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /Au channels show pn junction features. Both channels displayed metal-oxide-semiconductors (MOS) capacitance-voltage characteristics. In addition, the analyses of the current-voltage characteristics have shown that the currents in the Yb/InSe/Au and Yb/InSe/SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> (30 nm)/Au channel are dominated by electric field-assisted thermionic emission (tunneling) of charge carriers through barriers of widths of 18/14 and 30/16 nm under reverse-/forward-biasing conditions, respectively. Further increase in the oxide layer thickness lowered the barrier height of the devices. On the other hand, when an ac signal of low amplitude is imposed through the device channels, the conductance, capacitance, and reflection coefficient spectra displayed bandstop filter characteristics near 1.6 GHz. The microwave cutoff frequency spectra show a remarkable increase in the cutoff frequency values as a result of the coating of InSe with SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> nanosheets. The features of the device assure its applicability as rectifying diodes, fast photosensors, MOS capacitors, and microwave bandstop filters.

Yb/InSe/Sb2Te3/Au BROKEN GAP HETEROJUNCTION DEVICES DESIGNED AS CURRENT RECTIFIERS, TUNABLE MOS CAPACITORS AND GIGAHERTZ MICROWAVE CAVITIES

Herein, we report the design and experimental characterization of a broken gap heterojunction devices fabricated by vacuum evaporation of Yb/InSe/Sb2Te3/Au stacked layers. The structural characterizations of the stacked layers revealed an amorphous/polycrystalline heterojunction type. The measurements of capacitance-voltage characteristics in the frequency domain of 1.0-9.0 MHz displayed tunable metal-oxidesemiconductor (MOS) characteristics. The frequency dependent built-in voltage, depletion width, and free carrier density is also investigated. In addition, the analyses of currentvoltage characteristics have shown that the device displays highly stable current rectification ratios of ~103 above 0.20 V. Moreover, the ac signal analyses in the frequency domain of 10-1800 MHz have shown the possible tunability of the conductance and capacitance over a wide range of frequency. Furthermore, the microwave cutoff frequency spectra indicated increasing cutoff frequency limits with increasing incident signal frequency. The microwave cutoff frequency reached 7.1 GHz for a propagating signal of frequency of 1800 MHz.

Flat cutoff probe for real-time electron density measurement in industrial plasma processing

The microwave cutoff probe (CP) is an accurate diagnostic technique to measure absolute electron density even in processing gas plasmas. Because this technique needs the installation of two probe tips and a probe body in the plasma chamber, it may cause plasma perturbation in semiconductor plasma processing; this may increase the uncertainty of the measured value. In this work, a flat CP, which is embedded in the substrate chuck or chamber wall, is proposed to measure electron density without plasma perturbation and to monitor processing plasma in real-time. We first evaluated the performance of various types of flat CPs, such as the point CP, ring CP, and bar cutoff probe (BCP), through electromagnetic (EM) field simulation. The BCP showed better performance with clearer cut-off signal characteristics and minimization of noise signals compared with the other probe types. Therefore, we focused on the characteristics of the BCP through experiments and/or EM simulations and concluded the followings: (i) the measured electron densities of the BCP agree well with those of the conventional CP; (ii) the BCP measures the plasma density near the plasma-sheath boundary layer, which is very closely adjacent to the chamber wall or wafer; (iii) it was demonstrated for the first time that the plasma density can be measured, even though the processing wafers such as un-doped silicon, P type silicon, amorphous carbon, or amorphous carbon/SiO2 patterned wafers were placed on the flat CP; and (iv) we performed real-time measurements of the electron density using the BCP covered with the wafers in plasmas with various process gases, such as Ar, NF3, and O2. These results indicate that the chuck-embed-type or wall-type flat CP can be used as a real-time electron density measurement (monitoring) tool during industrial plasma processing, such as during etching, deposition, sputtering or implantation, and the chuck-embed-type flat CP can measure the plasma density impinging on the wafer in real-time without stopping the processing.

Formation, negative capacitance and negative conductance effects in Selenium stacked layers sandwiched with Ag nanosheets

In this work, we report the nature of formation in the presence and absence of Ag nanosheets being inserted between of two stacked layers of Se thin films which are grown onto Au substrates. The Se/Se and Se/Ag/Se films which are prepared by the thermal evaporation technique under vacuum pressure of 10−5 mbar are studied by means of x-ray diffraction, conductance and capacitance spectroscopy techniques in the frequency domain of 0.01–1.80 GHz. Metal inducted crystallization processes from amorphous to hexagonal phases are achieved by using the Au substrate. The presence of Ag nanosheets of thicknesses of 50 nm between two 500 nm thick stacked layers of Se strongly affects the structural parameters through increasing the lattice constants, the microstrain and the defect density and decreasing the crystallite size. While the two stacked layers of Se sandwiched between Au and In metals displayed negative conductance effect associated with resonance in the capacitance and maximum microwave cutoff frequency () of 0.68 GHz near 1.31 GHz, the insertion of Ag nanosheets forced the two stacked layers to exhibit higher positive conductance values and increased the values to 17.4 GHz. Ag nanosheets also caused negative capacitance (NC) effect in all the studied frequency domain. NC effect is associated with resonance-anti-resonance phenomena in the region of 1.33–1.37 GHz. The features of the selenium stacked layers make them attractive for use in microwave circuits as cavities, noise reducers, parasitic capacitance cancellers and bandpass filters.

Plasma density measurement and downstream etching of silicon and silicon oxide in Ar/NF3 mixture remote plasma source

In this study, plasma density measurements were performed near the plume region of the remote plasma source (RPS) in Ar/ gas mixtures using a microwave cutoff probe. The measured plasma density is in the range of 1010–1011 cm−3 in the discharge conditions with RPS powers of 2–4 kW and gas pressures of 0.87–4 Torr. The plasma density decreased with increasing gas pressures and RPS powers under various Ar/ mixing ratios. This decrease in the plasma density measured at the fixed measurement position (plume region) can be understood by the reduction of the electron energy relaxation length with increases in the gas pressures and mixing ratio of We also performed downstream etching of silicon and silicon oxide films in this system. The etch rate of the silicon films significantly increases while the silicon oxide is slightly etched with the gas pressures and powers. It was also found that the etch rate strongly depends on the wafer position on the processing chamber electrode, and that the etch selectivity reached 96–131 in the discharge conditions of RF powers (3730–4180 W) and gas pressures (3.6–4 Torr).

ZnSe/Al/ZnSe nanosandwiched structures as dual Terahertz–Gigahertz signal receivers

In the current work, we focus on the enhancements in performance of the ZnSe terahertz/gigahertz signal receivers which are achieved by the insertion of nanosheets of Al layers of thickness of 30 nm between two 500 nm thick layers of ZnSe. The Al nanosandwiching which decreased the defect density, stacking faults and increased the grain size in the films increased the optical conductivity by more than 125%, increased the drift mobility to 313 cm2 V−1 s−1 and widens the plasmon frequency ranges to 0.49–4.92 GHz. In addition, the analysis of the terahertz cutoff () frequency spectra have shown that the presence of Al nanosheets improves the cutoff frequency value by three orders of magnitude making the ZnSe receivers more suitable for visible light and IR communication technology. The value of is 49.6 THz when light signal of wavelengths of 408 nm that suits blue lasers is irradiated. Moreover, the impedance spectroscopy analysis in the gigahertz frequency domain has shown that the Al sandwiched ZnSe exhibits negative capacitance spectra in the frequency domain of 0.01–1.04 GHz. This property is useful for parasitic capacitance cancelling and noise reducing in circuits. Furthermore, the study of the microwave cutoff frequency spectra has shown that the value of is enhanced by three orders of magnitude above 1.5 GHz.

Fabrication and characterization of Yb/MoO3/(C,Yb) devices

In this study we have explored some of the properties of Yb/MoO3/(C, Yb) thin films as a multifunctional optoelectronic device. While the MoO3 films which are deposited onto glass substrate are found to be of amorphous nature, the Yb metal induced the growth of orthorhombic phase of MoO3. The films are high transparent and exhibit energy band gap value of 3.0 eV which make it sensitive to light signals in the near ultraviolet range of light. In addition, the frequency dependent capacitance-voltage characteristics of Yb/MoO3/(C,Yb) structure display pronounced accumulation, depletion and inversion regions that nominate it for use as tunable metal-oxide-semiconductor MOS device. The physical parameters including the built in voltage, barrier height, flat band and threshold voltages of the MOS capacitors are also determined. Furthermore, the current-voltage characteristics displayed high rectification ratio that could reach 1.26 × 104 at biasing voltage of 0.5 V nominating the Yb/MoO3/C device for use as electronic switches. On the other hand, the impedance spectroscopy analysis in the frequency domain of 0.01–1.80 GHz, have shown that the Yb/MoO3/Yb structures are more appropriate for microwave applications than Yb/MoO3/C device. The microwave cutoff frequency for the Yb sandwiched MoO3 exceeds 140 GHz. The return loss for the Yb/MoO3/Yb reaches 26 dB at 1.8 GHz. These values are attractive as they suit microwave low/high pass band filters.

Characterization of the Al/Ge/In2Se3/Ga2S3/Al hybrid tunneling barriers designed for Gigahertz/Terahertz applications

In the current work, we report the design and performance of a tunneling amorphous thin film hybrid device made of Ge/In2Se3/Ga2S3 sandwiched between two aluminum thin films. Each of the stacked semiconducting layers are of 200 nm thicknesses. The hybrid device which is composed of a p-n junction between two Schottky shoulders is designed to have two valence band offsets of 0.59 and 0.84 eV at the Ge/In2Se3 and at In2Se3/Ga2S3 interfaces, respectively. The offsets which caused two quantum confinements forces the device to exhibit field effect assisted thermionic and thermionic transport mechanisms under the reverse and forward biasing conditions, respectively. When an alternating current signal is imposed between the terminals of the device, the device conducted by the quantum mechanical tunneling of charge carriers and by the correlated barrier hopping above and below 0.180 GHz, respectively. The hybrid structure are also observed to exhibit series and parallel resonance at the switching frequency between the two conduction mechanisms. It also exhibited negative differential capacitance effect in the frequency domain of 0.18–1.80 GHz. For the Al/Ge/In2Se3/Ga2S3/Al hybrid structure the microwave cutoff frequency reached 100 GHz. The latter value is promising as it indicates the ability of using the device as fast switches and microwave/Tera wave traps.

Development of a miniature microwave electron cyclotron resonance plasma ion thruster for exospheric micro-propulsion

A miniature microwave electron cyclotron resonance plasma source [(discharge diameter)/(microwave cutoff diameter) < 0.3] has been developed at Kyushu University to be used as an ion thruster in micro-propulsion applications in the exosphere. The discharge source uses both radial and axial magnetostatic field confinement to facilitate electron cyclotron resonance and increase the electron dwell time in the volume, thereby enhancing plasma production efficiency. Performance of the ion thruster is studied at 3 microwave frequencies (1.2 GHz, 1.6 GHz, and 2.45 GHz), for low input powers (<15 W) and small xenon mass flow rates (<40 μg/s), by experimentally measuring the extracted ion beam current through a potential difference of ≅1200 V. The discharge geometry is found to operate most efficiently at an input microwave frequency of 1.6 GHz. At this frequency, for an input power of 8 W, and propellant (xenon) mass flow rate of 21 μg/s, 13.7 mA of ion beam current is obtained, equivalent to an calculated thrust of 0.74 mN.