Method of fabricating organic LED matrices

• US 5,641,611 A
• Filed: 08/21/1995
• Issued: 06/24/1997
• Est. Priority Date: 08/21/1995
• Status: Expired due to Term

• Current Assignee: Universal Display Corporation
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Lee, Hsing-Chung, Shieh, Chan-Long
• Primary Examiner(s): ANGEBRANNDT, MARTIN J
• Application Number:
  US08/517,223
• Time in Patent Office: 673 Days
• Field of Search: 437/1, 437/80, 437/89, 437/905, 437/944, 257/40, 257/79, 257/89, 257/88, 427/468, 427/466, 427/487, 427/66, 427/68, 427/69, 427/99, 427/155, 427/162, 427/256, 427/259, 427/261, 427/265, 427/282, 430/314, 430/315, 430/320, 430/321, 430/324, 430/23, 430/24, 430/29
• US Class Current: 430/321
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 71/16 using physical vapour deposition [PVD], e.g. vacuum deposition or sputtering
• CPC Class Codes: H10K 71/166 using selective deposition, e.g. using a mask

Abstract

Items of material are patterned on a substrate by forming a layer of photoresist on the substrate and a layer of metal on the photoresist. The photoresist is patterned to define an opening exposing a portion of the substrate and the metal is patterned to define an aperture smaller than the opening so as to divide the exposed surface of the substrate into shadow areas and a non-shadow area. A first material system is evaporated generally perpendicular to the aperture to form a first organic light emitting diode on the surface of the substrate in the non-shadow area and second and third material systems are evaporated at angles to the aperture to form second and third organic light emitting diodes in the shadow areas. Passivation material is evaporated perpendicularly onto the first diode and at the angle onto the second diode.

Claims

1. A method of patterning items of material on a supporting substrate comprising the steps of:

providing a supporting substrate with first and second laterally spaced apart conducting areas defined on the substrate, the first and second conducting areas defining first electrical contacts;

forming a first layer of removable material on the substrate and a second layer of removable material on the first layer of removable material;

forming an aperture through the second layer of removable material overlying the first conducting area and forming an opening through the first layer of removable material positioned between the aperture and the first and second conducting areas, remaining portions of the first layer of removable material defining the opening therein with a first transverse dimension exposing a portion of the surface of the substrate and remaining portions of the second layer of removable material defining the aperture therethrough with a second transverse dimension, smaller than the first transverse dimension, the second layer of removable material overlying a portion of the exposed surface of the substrate in the opening so as to divide the exposed surface of the substrate into a shadow area surrounding the first conducting area and a non-shadow area surrounding the second conducting area; and

depositing a first material system, including a light emissive material and a second electrical contact, by evaporating the first material system in a vacuum chamber at a distance from the aperture so that evaporated particles of the first material system move toward the exposed surface of the substrate in generally parallel lines which are generally perpendicular to the aperture to form a first multi-layered electrical device of the first material system on the second conducting area of the surface of the substrate in the non-shadow area and depositing a second material system, including a light emissive material and a second electrical contact, by evaporating the second material system in a vacuum chamber at a distance from the aperture so that evaporated particles of the second material system move toward the exposed surface of the substrate in generally parallel lines which are at an angle to the aperture to form a second multi-layered electrical device of the second material system on the first conducting area of the surface of the substrate in the shadow area, the first and second multi-layered devices being laterally spaced apart in non-overlapping relationship; and

removing the first and second layers of removable material from the substrate.

2. A method of patterning items of material on a supporting substrate as claimed in claim 1 wherein the step of depositing the first layer of removable material includes depositing a layer of photoresist material.

3. A method of patterning items of material on a supporting substrate as claimed in claim 1 wherein the step of forming the second layer of removable material includes depositing a first layer of metal on the layer of removable material.

4. A method of patterning items of material on a supporting substrate as claimed in claim 1 wherein depositing the first material system to form a first multi-layered electrical device and depositing the second material system to form a second multi-layered electrical device each include depositing a first material system forming a first color organic light emitting diode and depositing a second material system forming a second color organic light emitting diode.

5. A method of patterning items of material on a supporting substrate as claimed in claim 1 wherein the step of providing the supporting substrate with first and second laterally spaced apart conducting areas defined on the substrate includes providing a base with a conductive layer positioned thereon and an insulating layer positioned on the conducting layer and having cavities with selected horizontal dimensions defined therethrough to expose portions of the conductive layer, which exposed portions define the first and second laterally spaced apart conducting areas.

6. A method of patterning items of material on a supporting substrate as claimed in claim 5 wherein the step of providing the supporting substrate further includes selecting the horizontal dimensions of the cavities to determine the relative amounts of electrical conduction of the items, the electrical conduction being determined by the size of the first and second laterally spaced apart conducting areas.

7. A method of patterning items of material on a supporting substrate as claimed in claim 5 wherein depositing the first material system, and depositing the second material system, each include depositing an organic electron emitter material on the exposed portions of the conductive layers in the cavities and depositing a second layer of conductive material on the organic electron emitter material in an overlaping relationship to each of the cavities.

8. A method of patterning items of material on a supporting substrate as claimed in claim 7 wherein depositing the organic electron emitter material on the exposed layer of conductive material and the second layer of conductive material on the organic emitter material further includes depositing one of a hole transport layer between the exposed portions of conductive material and a layer of organic electron emitter material or an electron transport layer between the second layer of conductive material and the layer of organic electron emitter material.

9. A method of patterning items of material on a supporting substrate as claimed in claim 1 including, subsequent to the step of depositing the first and second material systems, the steps of depositing passivation material by evaporating the passivation material in a vacuum chamber at a distance from the aperture so that evaporated particles of the second material system move toward the exposed surface of the substrate in generally parallel lines which are generally perpendicular to the aperture to form a passivation cover on the first material system in the non-shadow area and depositing passivation material by evaporating the passivation material in a vacuum chamber at a distance from the aperture so that evaporated particles of the second material system move toward the exposed surface of the substrate in generally parallel lines which are at an angle to the aperture to form a passivation cover on the second material system in the shadow area.

10. A method of patterning items of material on a supporting substrate as claimed in claim 9 wherein the steps of depositing passivation material generally perpendicular to the aperture and depositing passivation material at an angle to the aperture each include dithering deposition sources about the perpendicular and the angle to form the passivation covers.

11. A method of patterning items of material on a supporting substrate as claimed in claim 1 wherein the steps of depositing the second material system at an angle to the aperture includes depositing the second material system at an angle dependent upon the second transverse dimension of the aperture and the depth of the opening.

12. A method of patterning three items of material on a supporting substrate comprising the steps of:

providing a supporting substrate with first, second and third laterally spaced apart conducting areas defined on the substrate, the first, second and third conducting areas each defining first electrical contacts;

forming a first layer of removable material on the substrate and a second layer of removable material on the first layer of removable material,

forming an aperture through the second layer of removable material overlying the first conducting area and forming an opening through the first layer of removable material positioned between the aperture and the first, second and third conducting areas, remaining portions of the first layer of removable material defining the opening with a first transverse dimension therein exposing a portion of the substrate and remaining portions of the second layer of removable material defining therein the aperture with a second transverse dimension, smaller than the first transverse dimension, the second layer of removable material overlying portions of the exposed substrate in the opening so as to divide the exposed substrate, respectively, into a first shadow area surrounding the first conducting area, a non-shadow area surrounding the second conducting area, and a second shadow area surrounding the third conducting area; and

evaporating a first material system, including a light emissive material and a second electrical contact, in a vacuum chamber at a distance from the aperture so that evaporated particles of the first material system move toward the exposed surface of the substrate in generally parallel lines which are generally perpendicular to the aperture to form an item of the first material system on the substrate in the non-shadow area, the first material system forming a first color organic light emitting diode;

evaporating a second material system, including a light emissive material and a second electrical contact, in a vacuum chamber at a distance from the aperture so that evaporated particles of the first material system move toward the exposed surface of the substrate in generally parallel lines which are at an angle to the aperture to form an item of the second material system on the substrate in the first shadow area, the second material system forming a second color organic light emitting diode; and

evaporating a third material system, including a light emissive material and a second electrical contact, in a vacuum chamber at a distance from the aperture so that evaporated particles of the first material system move toward the exposed surface of the substrate in generally parallel lines which are at another angle to the aperture to form an item of the third material system on the substrate in the second shadow area, the third material system forming a third color organic light emitting diode;

the first color, second color and third color organic light emitting diodes being laterally spaced apart in non-overlapping relationship; and

removing the first and second layers of removable material from the substrate.

13. A method of patterning items of material on a supporting substrate as claimed in claim 12 including, subsequent to the steps of evaporating first, second and third material systems and before the step of removing the first and second layers of material from the substrate, the steps of evaporating a passivation material in a vacuum chamber at a distance from the aperture so that evaporated particles of the first material system move toward the exposed surface of the substrate in generally parallel lines which are generally perpendicular to the aperture to form a passivation cover on the first material system in the non-shadow area, evaporating the passivation material in a vacuum chamber at a distance from the aperture so that evaporated particles of the first material system move toward the exposed surface of the substrate in generally parallel lines which are at an angle to the aperture to form a the passivation cover on the second material system in the first shadow area and evaporating passivation material in a vacuum chamber at a distance from the aperture so that evaporated particles of the first material system move toward the exposed surface of the substrate in generally parallel lines which are at another angle to the aperture to form a passivation cover on the third material system in the second shadow area.

14. A method of patterning items of material on a supporting substrate as claimed in claim 13 wherein the steps of evaporating the passivation material generally perpendicular to the aperture, evaporating the passivation material at an angle to the aperture and evaporating the passivation material at another angle to the aperture each include dithering evaporation sources about the perpendicular, the angle and the another angle to form the passivation covers.

15. A method of patterning items of material on a supporting substrate as claimed in claim 12 wherein the step of forming the second layer of removable material includes depositing a layer of metal on the first layer of removable material.

16. A method of patterning items of material on a supporting substrate as claimed in claim 12 wherein the step of providing the supporting substrate with first, second and third laterally spaced apart conducting areas defined on the substrate includes providing a base with a conductive layer positioned thereon and an insulating layer positioned on the conducting layer and having cavities with selected horizontal dimensions defined therethrough to expose portions of the conductive layer, which exposed portions define the first, second and third laterally spaced apart conducting areas.

17. A method of patterning items of material on a supporting substrate as claimed in claim 16 wherein the step of providing the supporting substrate further includes selecting the horizontal dimensions of the cavities to determine the relative amounts of electrical conduction of the items, the electrical conduction being determined by the size of the first, second and third laterally spaced apart conducting areas.

18. A method of patterning and passivating, on a supporting substrate, items of material systems including organic light emitters, comprising the steps of:

providing a supporting substrate with first and second laterally spaced apart conducting areas defined on the substrate, the first and second conducting areas defining first electrical contacts;

forming a layer of removable material on the substrate and a layer of metal on the layer of removable material;

forming an aperture through the layer of metal overlying the first conducting area and forming an opening through the layer of removable material positioned between the aperture and the first and second conducting areas, remaining portions of the layer of removable material defining the opening therein with a first transverse dimension exposing a portion of the substrate and remaining portions of the layer of metal defining the aperture therethrough with a second transverse dimension, smaller than the first transverse dimension, the layer of metal overlying a portion of the substrate in the opening so as to divide the exposed substrate into a shadow area surrounding the first conducting area and a non-shadow area surrounding the second conducting area;

evaporating a first material system, including a light emissive material and a second electrical contact, in a vacuum chamber at a distance from the aperture so that evaporated particles of the first material system move toward the exposed surface of the substrate in generally parallel lines which are generally perpendicular to the aperture to form an item of the first material system including a first organic light emitter on the second conducting area of the substrate in the non-shadow area;

evaporating a second material system, including a light emissive material and a second electrical contact, in a vacuum chamber at a distance from the aperture so that evaporated particles of the second material system move toward the exposed surface of the substrate in generally parallel lines which are at an angle to the aperture to form an item of the second material system including a second organic light emitter on the first conducting area of the substrate in the shadow area, the first and second multi-layered devices being laterally spaced apart in non-overlapping relationship;

evaporating passivation material in a vacuum chamber at a distance from the aperture so that evaporated particles of the passivation material move toward the first material system in generally parallel lines which are generally perpendicular to the aperture to form a passivation cover on the first material system;

evaporating passivation material in a vacuum chamber at a distance from the aperture so that evaporated particles of the passivation material move toward the second material system in generally parallel lines which are at an angle to the aperture to form a passivation cover on the second material system; and

removing the layer of removable material and the layer of metal on the layer of removable material.