Many aspects of the present method for manufacturing a cathode assembly of a field emission display can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present method for manufacturing a cathode assembly of a field emission display. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
Reference will now be made to the drawings to describe a preferred embodiment of the present method for manufacturing a cathode assembly of a field emission display, in detail.
Referring to
providing a substrate;
forming a cathode on the substrate;
forming an electrically insulating layer on the cathode;
forming a gate electrode layer on the first electrically insulating layer;
forming a photoresist layer on the gate electrode layer;
defining at least one opening in the photoresist layer using a photolithographic process;
etching the gate electrode layer through the at least one opening in the photoresist layer so as to form at least one gate electrode opening in the gate electrode layer;
etching the electrically insulating layer to define at least one cavity in the electrically insulating layer;
pressing the photoresist layer in a manner such that a size of the at least one opening in the photoresist layer is reduced;
depositing a catalyst layer on the substrate in the at least one cavity through the at least one opening; and
growing carbon nanotubes on the catalyst layer.
Referring to
Alternatively, the substrate 110 may be comprised of transparent conducting material, such as indium tin oxide (ITO) or indium zinc oxide (IZO), etc. In which case the substrate 110 can be directly used as a cathode.
Referring to
The electrically insulating layer 120 is used to form an insulating layer between the cathode 113 and the gate electrode layer 130. The electrically insulating layer 120 can be deposited on the substrate 110 by methods involving evaporation, printing, etc. The electrically insulating layer 120 has a thickness in an approximate range from 1 micrometer to 1000 micrometers. Preferably, the thickness of the electrically insulating layer 120 is in an approximate range from 10 micrometers to 200 micrometers. The electrically insulating layer 120 is comprised of a material capable of resisting high temperatures of about 700 degrees centigrade, such as high temperature glass, silicon, silicon oxide, ceramic, or mica, etc.
The gate electrode layer 130 is insulated from the cathode 113 through the electrically insulating layer 120 and is used to form gate electrodes.
The photoresist layer 140 is formed on the gate electrode layer 130 to be used as a mask.
Referring to
The at least one opening 141 in the photoresist layer 140 is formed and the remaining photoresist layer 140 forms a pattern corresponding to the designed gate electrodes. Advantageously, the photoresist layer 140 has an area corresponding to the designed gate electrodes.
Referring to
The gate electrode layer 130 can be etched using dry etching methods. The photoresist layer 140 can be used as a mask in the dry etching process, and at least one gate electrode opening 131 corresponding to the at least one opening 142 in the photoresist layer 140 can be formed in this way. The obtained gate electrode layer 130 serves as the gate electrodes. The electrically insulating layer 120 can be etched using wet etching methods. The photoresist layer 140 and the gate electrode layer 130 can be used as a mask in the wet etching process, and can be used to define at least one cavity 121. The obtained electrically insulating layer 130 serves as the spacer.
Referring to
The photoresist layer 140 is softened by heating and then is pressed to decrease its thickness and increase its area and the at least one opening 141 in the photoresist layer 140 is reduced as a result. Compared with the at least one gate electrode opening 131, a size of the at least one opening 141 in the photoresist layer 140 is smaller than a size of the gate electrode opening 131.
Referring to
The catalyst layer 170 is comprised of a material selected from a group consisting of iron (Fe), cobalt (Co), nickel (Ni), and any alloys thereof. The catalyst layer 170 has a thickness in an approximate range from 1 nanometer to 10 nanometers. Preferably, the thickness of the catalyst layer 170 is in an approximate range from 3 to 5 nanometers. Furthermore, since the size of the at least one opening 141 in the photoresist layer 140 is smaller than the at least one gate electrode opening 131, the catalyst layer 170 in the at least one cavity 121 is smaller than the at least one gate electrode opening 131.
Referring to
The carbon nanotubes 180 are grown by chemical vapor deposition methods and have an growing area similar to the metal catalyst layers 170. Therefore, the growing area of the carbon nanotubes 180 is smaller than the gate electrode opening 131.
Referring to
Compared with the conventional method for manufacturing the cathode assembly of the field emission display, the present method has many advantages. Since the catalyst layer 170 is deposited through the opening 141 in the photoresist layer 140, the catalyst layer 170 is smaller than the gate electrode opening 131, and the grown carbon nanotubes 180 from the catalyst layer 170 have a growing area smaller than the gate electrode opening 131, therefore the cathode assembly prevents carbon nanotubes 180 from contacting with the gate electrode layer 130. The probability of short circuit between the gate electrode layer 130 and the carbon nanotubes 180 is eliminated. Furthermore, the probability of electron emitted from the carbon nanotubes 180 transmitting to the gate electrode layer 130 is decreased. The method is simple and costs less since no any other material is used and no additional steps are needed.
Referring to
It is to be understood that the above-described embodiment is intended to illustrate rather than limit the invention. Variations may be made to the embodiment without departing from the spirit of the invention as claimed. The above-described embodiments are intended to illustrate the scope of the invention and not restricted to the scope of the invention.
Number | Date | Country | Kind |
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200610061097.2 | Jun 2006 | CN | national |
This application is related to a commonly-assigned copending application Ser. No. ______, entitled “CARBON NANOTUBE FIELD EMISSION DEVICE AND METHOD FOR MANUFACTURING SAME”(attorney docket number US 10725). Disclosure of the above-identified application is incorporated herein by reference.