Planar electron emitter (PEE), display using it and method for transmitting electron

Abstract

A planar electron emitter, based on the existence of quasi-ballistic transport of electrons is disclosed. In its preferred embodiment the planar electron emitter structure consists of a body of finite gap pure semiconductor or insulator, the said body of macroscopic thickness (~1 mm) being terminated by two parallel surfaces and of a set of two electrodes deposited / grown on the said two free surfaces such that when a low external electrical field (~100 V / cm) is applied to this structure, consisting of two electrodes and the said semiconductor or insulating body sandwiched between them, a large fraction of electrons injected into the said semiconductor or insulator body from the negatively charged electrode (cathode) is quasi-ballistic in nature, that is this fraction of injected electrons is accelerated within the said semiconductor or insulator body without suffering any appreciable inelastic energy losses, thereby achieving sufficient energy and appropriate momentum at the positively charged electrode (anode) to be able to traverse through the said anode and to escape from the said structure into empty space (vacuum), said semiconductor or insulator body comprises a material or material system having a predetermined crystal orientation.

Description

technical field [0001] The present invention relates to a new method of generating and conducting quasi-ballistic electrons using semiconductor or insulator substrates when exposed to low electric fields. This approach would make it possible to accelerate electrons within the semiconductor or insulator without suffering any appreciable inelastic energy loss. Its main examples will be planar electron emitters, eg in flat panel displays and planar electron beam lithography. Background technique [0002] A number of devices using the (disclosed) planar electron emitters in various fields of application are also disclosed, and priority is also claimed for said devices. [0003] The present invention relates to the quasi-ballistic transport of electrons in high resistance semiconductors or insulators when exposed to low electric fields (approximately 100 V / cm). Quasi-ballistic transport means that electron scattering is minimized so that the electron mean free path becomes visi...

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Problems solved by technology

However, this susceptible electron emitter has other disadvantages: planar electron emitters suitable for this purpose can expose the entire wafer with a wide electron beam, but, at the necessary voltage, due to the necessary high electric field and short distance effect resulting in the extremely short lifetime of these planar electron emitters

[0065] A disadvantage of existing field emission planar electronic devices is that high external voltages must be applied over relatively short distances (on the order of the mean free path of electrons) in order to generate an electric field high enough to facilitate the emission and acceleration of electrons.

[0066] Another disadvantage is that this requirement to apply a relatively high local electric field over a relatively short distance, together with the quality of the material obtained, results in a shortened electron mean free path (increased scattering ratio), which in turn results in establishes a limit on the possible practical distances within the device that electrons can travel without too appreciable loss of energy

[0067] There is also the disadvantage that, due to the results mentioned above, only a fraction of these electrons have enough energy to escape the anode (emitting) surface into the space adjacent to the cathode-anode structure

[0068] Another disadvantage is that these devices usually have a rather small electron emission current I em ( figure 2 ) with a large background current I back ( figure 2 )

[0069] Yet another disadvantage of existing field emission planar electronic devices is that they suffer from weaknesses such as excessive electrical power dissipation per square centimeter of electron emitting surface area

[0070] Yet another disadvantage is that the above result leads to low electron emission efficiency

[0071] Yet another disadvantage of existing field emission planar electronic devices is that they are often unstable and prone to dielectric breakdown, which often severely limits their lifetime

[0072] Yet another disadvantage of the devices is that they suffer from frequent overheating due to large energy losses in the critical regions of the devices (in the range of high electric fields at very short distances)

[0073] Yet another disadvantage is that the scaling up of these planar electron field emission devices (increasing the electron emitting area of ​​the cathode) poses a serious problem

[0074] Yet another disadvantage of the devices is that they use expensive non-standard materials

[0075] Another shortcoming of existing field emission planar electronic devices is that the structure is too complicated

[0076] A further disadvantage of planar electron emitters emitting a wide electron beam suitable for exposing wafers in IC fabrication processes is their extremely short lifetime (less than 30 minutes), which makes them unsuitable for planar e-beam lithography

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