JPH04146673A - Thin film semiconductor device - Google Patents

Abstract

PURPOSE:To enable a thin film semiconductor device to be mass-produced by a method wherein a semiconductor thin film substrate is left overhanging from the side face of a contact hole, where the contact hole is provided to an insulating film formed on the semiconductor thin film substrate, and an electrode is formed on self-alignment with the overhang concerned. CONSTITUTION:A contact hole is provided through dry etching to a CVD SiO2 film 4 formed on an Si film 3 provided onto an SiO2 film 2 which is formed on the surface of an Si substrate 1. When the Si film 3 is etched, the dry etching selection ratio of SiO2 to Si is set large up to 20:1 or so or a wet etching process is additionally conducted after a dry etching process is carried out, so that an overhang 6 is formed sloping or trapezoidal, and then an electrode 5 is formed, whereby the Si film 3 and the electrode 5 can be surely electrically connected together in a mass production manner. It is not necessary that the Si film 3 is provided to all the surface of the contact hole, the Si film 3 is previously provided to a part of the contact hole, and the overhang 6 may be provided not to all the peripheral part of the contact hole but to a part of the peripheral part of the contact hole.

Description

[Detailed description of the invention] [Industrial application field] The present invention is a core of a thin film semiconductor device. do.

Regarding Contact Structure [Prior Art] Conventionally, a contact structure of a thin film semiconductor device has a structure as shown in a cross-sectional view in FIG. That is, 500μ
o5μm5μm thickness i02 on Si substrate 11 with a thickness of about m
81 film 16 with a thickness of about 0.1 μm formed on the film 12
Through a contact hole made by wet etching in the film 14,
It was customary for the electrodes 15 to be connected.

[Problem to be solved by the invention]

However, according to the above-mentioned conventional technology, the formation of contact holes by wet etching is limited to forming contact holes up to about 2 μmφ, and dry etching is required to form contact holes of about 2 μmφ or less. When etching is applied, the thickness is about 0.1 μm to 1 μm.
The problem is that the film is removed by etching and forming a contact structure using conventional techniques is practically impossible for mass production.

It is an object of the present invention to solve the problems of the prior art and to provide a contact structure for mass-produced thin film semiconductor devices.

[Means to solve the problem]

In order to solve the above problems, the present invention relates to a thin film semiconductor device, in which the semiconductor thin film substrate is passed through a contact hole formed in an insulating film formed on the semiconductor thin film substrate, and the semiconductor thin film substrate is left extending from the side surface of the contact hole. Measures are taken to form the electrode in self-alignment with the overhang.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to Examples.

FIG. 1 is a sectional view of a contact structure of a thin film semiconductor device, showing one embodiment of the present invention. That is, the Si substrate 1
Contact holes are formed on the S1 film 3 on the 5in2 film 2 formed on the 0 surface (!VD) by dry etching in the 5i02 film 4, and when etching the Si film 6, - Increase the etching selection ratio to about 20:1, or
After dry esoching, by adding a wet elastincula or the like to form a diagonal or trapezoidal protrusion 6 on the Si film 3, and then forming an electrode 5, Sj, a film 6,
Reliable connection with the electrode 5 can be made in mass production.

It should be noted that the S1 film 3 does not need to be present on the entire surface of the contact hole. Needless to say, it's okay if something happens.

〔Effect of the invention〕

The present invention has the advantage of being able to provide a contact structure for mass-produced thin film semiconductor devices.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a tactile structure of a thin film semiconductor device showing one embodiment of the present invention. FIG. 2 is a sectional view of a contact structure of a thin film semiconductor device according to the prior art. 1 substrate i02 film 1 film VD 5in2 Pole extension part 1 ...... S 2 ...... S 5 ...... S 4 ......・・・・・・ C 5・・・・・・・・・Electricity・・・・・・・・・Applicant Seiko Epson Corporation

Claims (1)

[Claims] Etching the semiconductor thin film substrate through a contact hole formed in an insulating film formed on the semiconductor thin film substrate, and leaving the semiconductor thin film substrate projecting from the side surface of the contact hole so as to be self-aligned with the projecting portion. A thin film semiconductor device characterized by forming electrodes.