Micro-machined electron transparent alumina vacuum windows

Al 2 O 3 thin films were deposited on silicon, steel and nickel substrates to fabricate MOS and MIM devices. The films were prepared by spray pyrolysis method using a spray solution of Aluminium acetyl acetonate dissolved in dimethyl formamide and this solution was sprayed on to the hot substrates at temperatures of 300 and 350 • C. The films were amorphous in nature as detected by XRD. Capacitance versus voltage (C-V), current versus voltage (I-V) and capacitance versus frequency (C-f) measurements were taken for these films. MOS capacitor was used as a humidity sensor using the home made humidity sensor setup. ac capacitance and parallel resistance of the capacitor as a function of humidity were studied. It was found that the capacitance value increases from 0.537 to 2.073 nf with the increase in relative humidity (RH) from 0 to 90% and the resistance decreases from 153 to 93 k with the increase in relative humidity from 20 to 87%. Relative dielectric constant versus temperature measurements were done for the MOS device to check its ferroelectric behavior and its critical temperature was found to be around 66 • C. MIM device was also used as a humidity sensor by measuring capacitance as a function of time by keeping the sensor in a dessicator. The 555 timer circuits were used to check the sensor behavior of the MOS device. Volume resistivity and breakdown electric field of the film deposited on steel were measured and found to be 5 × 10 11 cm and 5 MV/cm, respectively.

show abstract

“…Al 2 O 3 -SiO 2 composite layers have great potential for memory application in microelectronics [5].…”

Section: Introductionmentioning

confidence: 99%

Characterization of Al2O3 thin films prepared by spray pyrolysis method for humidity sensor

Shamala

Murthy

Radhakrishna

et al. 2007

Sensors and Actuators A: Physical

View full text Add to dashboard Cite

show abstract

“…The material used to make the windows should have at least the following three properties: (1) electron-transparent: only when the windows are sufficiently thin (typically less than 50 nm [19,21]), can atomic resolution TEM be achieved; (2) sturdy enough to tolerate gas pressure difference between two sides of the window; and (3) weakly diffracting so as not to interfere with the diffraction from the sample. The windows should be made of elements with a low atomic mass since the scattering power of electrons relies heavily on the weight of the atomic core [52,53]. In addition, amorphous materials are preferable as windows since the electron scattering can be randomized and the superposition of periodic diffraction patterns onto the microscope images can be prevented [19].…”

Section: Windowed Gas Cells (Closed Type Etem)mentioning

confidence: 99%

Advances in windowed gas cells for in-situ TEM studies

Yao

2015

Nano Energy

View full text Add to dashboard Cite

“…Electrons can penetrate a thin electron window and emit into ambient atmosphere. Electron window has some potential applications including energy dispersive X-ray spectroscopy (EDS) and electron microscopy in atmospheric use for portability and interplanetary exploration were reported [1,2].…”

Section: Introductionmentioning

confidence: 99%

Micro Proximity Electron Source with Apertured Electron Window for Nanolithography in Atmosphere

Cho

Ono

Esashi

2007

TRANSDUCERS 2007 - 2007 International Solid-State Sensors, Actuators and Microsystems Conference

View full text Add to dashboard Cite

A miniature electron source with small electron windows for use in atmospheric environment has been developed. Electron windows made of 50-nm thick silicon with sizes of 250 nm diameter and 1.5 µm square are fabricated at the bottom of an aperture. Electrons from carbon nanocoils as emitters can be emitted by field emission and transmitted into atmospheric pressure via submicron electron window. The transmittance via the electron window and current density are evaluated to be 4% and 90 pA/µm 2 , respectively. At the acceleration voltage of 10 kV, electrons penetrated the electron window, ant its pattern was transferred on resist.

show abstract

Micro-machined electron transparent alumina vacuum windows

Cited by 18 publications

References 19 publications

Characterization of Al2O3 thin films prepared by spray pyrolysis method for humidity sensor

Characterization of Al2O3 thin films prepared by spray pyrolysis method for humidity sensor

Advances in windowed gas cells for in-situ TEM studies

Micro Proximity Electron Source with Apertured Electron Window for Nanolithography in Atmosphere

Contact Info

Product

Resources

About