Method for forming a patterned semiconductor film

• US 6,498,114 B1
• Filed: 08/31/2000
• Issued: 12/24/2002
• Est. Priority Date: 04/09/1999
• Status: Expired due to Fees

• Current Assignee: E Ink Holdings Incorporated
• Original Assignee: E Ink Holdings Incorporated
• Inventors: Amundson, Karl, Drzaic, Paul S., Wang, Jianna, Duthaler, Gregg, Kazlas, Peter
• Primary Examiner(s): Smith, Matthew
• Assistant Examiner(s): Anya, Igwe U.
• Application Number:
  US09/651,710
• Time in Patent Office: 845 Days
• Field of Search: 438/780, 438/127, 438/694, 438/953, 438/738, 438/622, 438/623, 438/700, 438/99, 438/22, 438/23, 438/26, 438/36, 438/82, 438/714, 438/455, 438/106, 438/160, 438/29, 438/30, 438/35, 438/28
• US Class Current: 438/780
• CPC Class Codes: B41J 3/4076 printing on rewritable, bistable "electronic paper" by a focused electric or magnetic field
• CPC Class Codes: G02F 1/1334 based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals
• CPC Class Codes: G02F 1/1345 Conductors connecting electrodes to cell terminals
• CPC Class Codes: G02F 1/1362 Active matrix addressed cells G02F1/134336, G02F1/134363 take precedence
• CPC Class Codes: H10K 10/46 Field-effect transistors, e.g. organic thin-film transistors [OTFT] H10K10/43 takes precedence
• CPC Class Codes: H10K 10/462 Insulated gate field-effect transistors [IGFETs]
• CPC Class Codes: H10K 10/464 Lateral top-gate IGFETs comprising only a single gate
• CPC Class Codes: H10K 10/466 Lateral bottom-gate IGFETs comprising only a single gate
• CPC Class Codes: H10K 10/468 characterised by the gate dielectrics
• CPC Class Codes: H10K 19/00 Integrated devices, or assemblies of multiple devices, comprising at least one organic element specially adapted for rectifying, amplifying, oscillating or switching, covered by group H10K10/00
• CPC Class Codes: H10K 71/10 Deposition of organic active material
• CPC Class Codes: H10K 71/13 using printing techniques, e.g. ink-jet printing or screen printing
• CPC Class Codes: H10K 71/20 Changing the shape of the active layer in the devices, e.g. patterning
• CPC Class Codes: H10K 71/211 by selective transformation of an existing layer
• CPC Class Codes: H10K 71/221 by lift-off techniques
• CPC Class Codes: H10K 71/236 using printing techniques, e.g. applying the etch liquid using an ink jet printer

Abstract

A process for forming a pattern in a semiconductor film is provided. The process comprises the steps of: providing a substrate; providing an organic semiconductor film adjacent the substrate; and providing a destructive agent adjacent selected portions of the organic semiconductor film, the destructive agent changing a property of selected portions of the organic semiconductor film substantially through the full thickness of the organic semiconductor film such that the property of the selected portions of the organic semiconductor film differs from the property of remaining portions of the organic semiconductor film. A method for manufacturing a transistor comprises the steps of: providing a substrate; providing a gate electrode adjacent the substrate; providing a gate dielectric adjacent the substrate and the gate electrode; providing a source electrode and a drain electrode adjacent the gate dielectric; providing a mask adjacent the gate dielectric in a pattern such that the source electrode, the drain electrode, and a portion of the gate dielectric remain exposed; and providing a semiconductor layer comprising one of an organic semiconductor and a plurality of inorganic colloidal particles, adjacent the source electrode, the drain electrode, the portion of the gate dielectric and the mask, thereby forming the transistor, the semiconductor layer having a thickness less than a thickness of the mask.

Claims

1. A process for forming a pattern in a semiconductor film comprising the steps of:

a) providing a substrate;

b) providing an organic semiconductor film adjacent the substrate; and

c) providing a destructive agent adjacent selected portions of the organic semiconductor film, the destructive agent changing a property of the selected portions of the organic semiconductor film such that the property of the selected portions of the organic semiconductor film differs from the property of a remaining portion of the organic semiconductor film, wherein the property of the selected portions is changed substantially through the full thickness of the organic semiconductor film.

2. The process of claim 1 further comprising the step of d) providing at least one of a conductive element and an insulative element to provide a circuit.

3. The process of claim 1 wherein the destructive agent changes an electrical property of selected portions of the organic semiconductor film.

4. The process of claim 1 wherein step c) comprises dissolution of the selected portions of the organic semiconductor film.

5. The process of claim 4 wherein the destructive agent comprises a solvent.

6. The process of claim 5 wherein the destructive agent comprises a solvent and a gelling agent.

7. The process of claim 5 further comprising the step of d) evaporating the solvent after dissolving the organic semiconductor film.

8. The process of claim 1 wherein step c) comprises providing the destructive agent through a printing process.

9. The process of claim 8 wherein step c) comprises providing the destructive agent through a screen printing process.

10. The process of claim 1 wherein step c) comprises providing the destructive agent through a stamping process.

11. The process of claim 1 wherein the organic semiconductor layer comprises poly(alkyl thiophene) and the destructive agent comprises one of chloroform, toluene, and xylene.

12. A method for manufacturing a transistor comprising the steps of:

a) providing a substrate;

b) providing a gate electrode adjacent the substrate;

c) providing a gate dielectric adjacent the substrate and the gate electrode;

d) providing a source electrode and a drain electrode adjacent the gate dielectric;

e) providing a mask adjacent the gate dielectric in a pattern such that the source electrode, the drain electrode, and a portion of the gate dielectric remain exposed;

and

f) providing a semiconductor layer comprising one of an organic semiconductor and a plurality of inorganic colloidal particles, adjacent the source electrode, the drain electrode, the portion of the gate dielectric and the mask, thereby forming the transistor, the semiconductor layer having a thickness less than a thickness of the mask.

13. The method of claim 12 wherein step f) comprises printing the mask by f1) providing a solvent-based polymer adjacent the gate dielectric and f2) evaporating the solvent.

14. The method of claim 12 further comprising providing an electronic display medium comprising a plurality of microcapsules, each capsule comprising one of electrophoretic particles, suspended particles and bichromal sphere, and providing the semiconductor layer near the display medium for addressing the display medium.

15. The method of claim 12 further comprising providing a liquid crystal display medium and providing the semiconductor layer near the display medium for addressing the display medium.

16. The method of claim 12 wherein step f) comprises f1) printing a mask comprising polymer adjacent the gate dielectric and f2) curing the polymer.

17. The method of claim 12 wherein step g) comprises providing a semiconductor layer having a thickness of 1/50 to 1/1000 of a thickness of the mask.

18. A method for manufacturing a transistor comprising the steps of:

a) providing a substrate;

b) providing a gate electrode adjacent the substrate;

c) providing a gate dielectric adjacent the gate electrode and the substrate;

d) printing a mask adjacent the gate dielectric in a pattern such that a portion of gate dielectric remains exposed;

e) providing a semiconductor layer comprising one of an organic semiconductor and a plurality of inorganic colloidal particles, adjacent the mask and the portion of the gate dielectric, the semiconductor layer having a thickness less than a thickness of the mask;

f) removing the mask; and

g) forming a source electrode and a drain electrode adjacent the semiconductor layer and the gate dielectric, thereby forming the transistor.

19. The method of claim 18 further comprising providing an electronic display medium comprising a plurality of microcapsules, each capsule comprising one of electrophoretic particles, suspended particles and bichromal sphere, and providing the semiconductor layer near the display medium for addressing the display medium.

20. The method of claim 18 further comprising providing a liquid crystal display medium and providing the semiconductor layer near the display medium for addressing the display medium.

21. The method of claim 18 wherein step d) comprises printing the mask by d1) providing a solvent-based polymer adjacent the gate dielectric and d2) evaporating the solvent.

22. The method of claim 18 wherein step d) comprises d1) printing the mask comprising a polymer adjacent the gate dielectric and d2) curing the polymer.

23. The method of claim 18 wherein step f) comprises removing the mask using a solvent.

24. The method of claim 23 wherein the solvent comprises acetone.

25. The method of claim 18 wherein step e) comprises providing a semiconductor layer having a thickness of about 1/50 to 1/1000 of a thickness of the mask.

26. A process for forming a pattern in a semiconductor film comprising the steps of:

a) providing a substrate;

b) providing a release layer adjacent selected portions of the substrate;

c) providing an organic semiconductor film adjacent the release layer and the substrate; and

d) exposing the release layer to a solvent which dissolves the release layer without dissolving the organic semiconductor film, thereby removing the release layer and the organic semiconductor film adjacent the release layer without removing the organic semiconductor film adjacent the substrate.