TOUCH SCREEN SUBSTRATE AND METHOD OF MANUFACTURING THE SAME

• US 20110234536A1
• Filed: 10/13/2010
• Published: 09/29/2011
• Est. Priority Date: 02/02/2010
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Chin, Hong-Kee, Yeo, Yun-Jong
• Granted Patent: US 9,671,637 B2
• Time in Patent Office: Days
• US Class Current: 345/175
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/042 by opto-electronic means
• CPC Class Codes: H01L 27/12 the substrate being other than a semiconductor body, e.g. an insulating body
• CPC Class Codes: H01L 27/1214 comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs
• CPC Class Codes: Y10T 29/49105 Switch making

Abstract

In a touch screen substrate and a method of manufacturing the same, the touch screen substrate includes a base substrate, a light blocking pattern, a first sensing element and a first switching element. The light blocking pattern includes an inorganic layer formed on the base substrate and a light blocking layer formed on the inorganic layer, the light blocking layer transmitting an infrared light and absorbing a visible light. The first sensing element is formed on the light blocking pattern and senses the infrared light. The first switching element is electrically connected to the first sensing element. Thus, an undercut may be prevented from being formed at a lower portion of the light blocking pattern, and an adhesive strength between the light blocking pattern and the base substrate may be enhanced.

Claims

1. A touch screen substrate comprising:

a base substrate;

a light blocking pattern including an inorganic layer formed on the base substrate and a light blocking layer formed on the inorganic layer, the light blocking layer transmitting infrared light and absorbing visible light;

a first sensing element formed on the light blocking pattern and sensing the infrared light; and

a first switching element electrically connected to the first sensing element.

2. The touch screen substrate of claim 1, wherein the inorganic layer comprises silicon nitride or silicon oxide.

3. The touch screen substrate of claim 1, further comprising:

a residual layer formed on an entire region of the base substrate except for a region on which the inorganic layer is formed, and having a thickness smaller than a thickness of the inorganic layer, and

wherein the first switching element is formed on the residual layer.

4. The touch screen substrate of claim 1, wherein the inorganic layer has a thickness in a range of about 100 Å

to about 1,000 Å

, and the light blocking layer has a thickness in a range of about 1,500 Å

to about 5,000 Å

.

5. The touch screen substrate of claim 1, wherein the first sensing element comprises:

a first active pattern formed on the light blocking pattern;

a first sensing source electrode and a first sensing drain electrode formed on the first active pattern, wherein the first sensing source electrode and the first sensing drain electrode are spaced apart from each other; and

a sensing gate electrode overlapping the first active pattern.

6. The touch screen substrate of claim 5, wherein the light blocking layer comprises amorphous silicon germanium (a-SiGe) or amorphous germanium (a-Ge).

7. The touch screen substrate of claim 5, wherein the first sensing gate electrode contacts the light blocking pattern through a contact hole that partially exposes the light blocking pattern, the contact hole passing through a first insulating layer formed on the first active pattern and a second insulating layer formed on the first sensing source and drain electrodes.

8. The touch screen substrate of claim 5, wherein the first switching element comprises:

a first switching source electrode electrically connected to the first sensing drain electrode;

a first switching drain electrode spaced apart from the first switching source electrode,

a second active pattern overlapping each of the first switching source and drain electrodes; and

a first switching gate electrode overlapping the second active pattern.

9. The touch screen substrate of claim 1, further comprising:

a bias line connected to the first sensing element;

a first read-out line connected to the first switching element;

a first sensing gate line connected to the first switching element to apply a first gate signal to the first switching element; and

a second sensing gate line connected to the first sensing element to apply a second gate signal to the first sensing element.

10. The touch screen substrate of claim 9, further comprising:

a second sensing element connected to the bias line and sensing the visible light;

a second switching element connected to the second sensing element;

a third sensing gate line connected to the second switching element to apply a third gate signal to the second switching element; and

a second read-out line connected to the second switching element.

11. A method of manufacturing a touch screen substrate, the method comprising:

forming a light blocking pattern on a base substrate, the light blocking pattern including an inorganic layer and a light blocking layer formed on the inorganic layer, the light blocking layer transmitting infrared light and absorbing visible light;

forming a first sensing element on the light blocking pattern; and

forming a first switching element electrically connected to the first sensing element.

12. The method of claim 11, wherein forming the light blocking pattern comprises:

forming a sacrificial layer on the base substrate;

forming a parent light blocking layer on the base substrate having the sacrificial layer;

patterning the parent light blocking layer using an etching gas to form the light blocking layer; and

patterning the sacrificial layer to form the inorganic layer.

13. The method of claim 12, wherein forming the inorganic layer includes removing the sacrificial layer except for the inorganic layer to expose the base substrate.

14. The method of claim 12, wherein forming the inorganic layer further comprises:

partially removing the sacrificial layer to form a residual layer having a thickness smaller than an initial thickness of the sacrificial layer, wherein the first switching element is formed on the residual layer.

15. The method of claim 12, wherein the parent light blocking layer and the sacrificial layer are formed in a dry etching process using a photoresist pattern formed on the parent light blocking layer as an etching stopping layer.

16. The method of claim 11, wherein forming the first sensing element includes,

forming a first active pattern on the base substrate having the light blocking pattern to overlap the light blocking pattern,

forming a sensing source electrode and a sensing drain electrode on the base substrate having the first active pattern, the sensing source and drain electrodes being spaced apart from each other, and

forming a sensing gate electrode on the base substrate having the sensing source and drain electrodes.

17. The method of claim 16, wherein forming the first switching element includes,

forming a switching gate electrode on the base substrate,

forming a second active pattern on the base substrate having the switching gate electrode, and

forming a switching source electrode and a switching drain electrode on the base substrate having the second active pattern, the switching source and drain electrodes being spaced apart from each other.

18. The method of claim 17, wherein forming the sensing source and drain electrodes comprises forming the switching source and drain electrodes.

19. The method of claim 16, further comprising:

forming a first insulating layer between the light blocking pattern and the first active pattern;

forming a second insulating layer between the sensing source and drain electrodes, and the sensing gate electrode; and

partially removing the first and second insulating layers to form a contact hole partially exposing the light blocking pattern,

wherein the light blocking layer comprises amorphous silicon germanium (a-SiGe) or amorphous germanium (a-Ge), and wherein the light blocking pattern contacts the sensing gate electrode through the contact hole.

20. The method of claim 11, wherein forming the first sensing element further comprises forming a second sensing element sensing the visible light, and forming the first switching element further comprises forming a second switching element connected to the second sensing element.