Electro-optical device and semiconductor circuit

• US 20020030190A1
• Filed: 07/19/2001
• Published: 03/14/2002
• Est. Priority Date: 12/03/1998
• Status: Active Grant

• Current Assignee: Hisashi Ohtani, Jun Koyama, Shunpei Yamazaki
• Original Assignee: Hisashi Ohtani, Jun Koyama, Shunpei Yamazaki
• Inventors: Yamazaki, Shunpei, Koyama, Jun, Ohtani, Hisashi
• Granted Patent: US 6,407,430 B1
• Time in Patent Office: Days
• US Class Current: 257/72
• CPC Class Codes: G02B 27/017 Head mounted
• CPC Class Codes: G02F 1/13454 Drivers integrated on the active matrix substrate G02F1/136277 takes precedence
• CPC Class Codes: H01L 21/02381 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/0242 Crystalline insulating materials
• CPC Class Codes: H01L 21/02425 Conductive materials, e.g. metallic silicides
• CPC Class Codes: H01L 21/02488 Insulating materials
• CPC Class Codes: H01L 21/02532 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/02609 Crystal orientation
• CPC Class Codes: H01L 21/02672 using crystallisation enhancing elements
• CPC Class Codes: H01L 27/1277 using a crystallisation promoting species, e.g. local introduction of Ni catalyst
• CPC Class Codes: H01L 27/1296 adapted to increase the uniformity of device parameters
• CPC Class Codes: H01L 29/04 characterised by their crystalline structure, e.g. polycrystalline, cubic or particular orientation of crystalline planes characterised by physical imperfections H01L29/30
• CPC Class Codes: H01L 29/045 by their particular orientation of crystalline planes
• CPC Class Codes: H01L 29/78627 with a significant overlap between the lightly doped drain and the gate electrode, e.g. GOLDD
• CPC Class Codes: H01L 29/78684 having a semiconductor body comprising semiconductor materials of Group IV not being silicon, or alloys including an element of the group IV, e.g. Ge, SiN alloys, SiC alloys H01L29/7869 takes precedence

Abstract

A high performance circuit is formed by using a TFT with less fluctuation in characteristics, and a semiconductor device including such a circuit is formed. When the TFT is formed, first, a base film and a semiconductor film are continuously formed on a quartz substrate without exposing to the air. After the semiconductor film is crystallized by using a catalytic element, the catalytic element is removed. In the TFT formed in such a process, fluctuation in electrical characteristics such as a threshold voltage and a subthreshold coefficient is extremely small. Thus, it is possible to form a circuit, such as a differential amplifier circuit, which is apt to receive an influence of characteristic fluctuation of a TFT.

Claims

1. An electro-luminescence display device comprising a plurality of thin-film transistors formed over a same substrate, said thin-film transistors comprising:

a crystalline semiconductor film having a {110} plane orientation in channel formation regions of said thin-film transistors,

wherein 90% or more of crystal lattices having continuity at any crystal grain boundaries in said channel formation regions, and

wherein a standard deviation is 0.1 V or less when a collective of threshold voltages exhibited by the plurality of the respective thin-film transistors is made a population.