JPS63224354A - Semiconductor device - Google Patents

Abstract

PURPOSE:To obtain a high resistance region which can be arbitrarily controlled externally at its resistance value and has extremely small substrate space factor by providing wiring electrodes ohmically connected to both ends of a high resistance semiconductor layer, and a gate insulating film on the semiconductor layer controlled by one potential of the electrodes. CONSTITUTION:A high resistance semiconductor layer 3 covered through a field insulating film 2 on one main surface of a semiconductor substrate 1, gate insulating film 6 and gate electrode 7 formed on partial region of the layer 3, metal wirings 4a led through a contact hole from one end of the layer 3, and metal wirings 4b led through a contact hole from the other end of the layer 3 and connected to a gate electrode 7 are provided. The layer 3 having the electrode 7 varies the resistivity of a region contacted with the film 6 by an electric field effect by a voltage applied to both ends thereof. Thus, a semiconductor device having a high resistance region including an extremely small substrate space factor is easily obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor device, and particularly to the structure of a high resistance region included in a semiconductor device.

[Conventional technology]

FIG. 3 is a cross-sectional view of a high resistance region included in a conventional semiconductor device.
The metal wirings 4a and 4b are formed of a high-resistance semiconductor layer 3 provided through contact holes, and metal wirings 4a and 4b are drawn out from both ends thereof through contact holes. Here, 5 is an insulating film between the eyebrows.

[Problem that the invention seeks to solve]

However, according to this conventional structure, the resistive semiconductor layer 3
The resistivity of is determined only by the film quality of the semiconductor layer itself,
Since the structure is completely independent of the potential of the semiconductor substrate 1 as well as the potential of other parts, it is necessary to precisely control the width, length, thickness, etc. of the semiconductor layer in order to obtain the desired resistance value. In particular, if high resistance is to be obtained, a large area must be occupied.

SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide a semiconductor device having a high resistance region with an extremely small substrate occupation rate whose resistance value can be arbitrarily controlled from the outside.

[Means for solving problems]

According to the present invention, a semiconductor device includes a semiconductor substrate, a high-resistance semiconductor layer formed on one main surface of the semiconductor substrate via an insulating film, and ohmically connected to both ends of the high-resistance semiconductor layer. The semiconductor device includes a wiring electrode and a gate insulating film on the high-resistance semiconductor layer that is controlled by the potential of one of the wiring electrodes.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a sectional view of a high resistance region showing an embodiment of the present invention. According to this embodiment, the semiconductor device includes a semiconductor substrate 1, a high-resistance semiconductor layer 3 deposited on one principal surface of the semiconductor substrate via a field insulating film 2, and a partial region of the high-resistance semiconductor layer 3. The gate insulating film 6 and gate electrode 7 provided above, the metal wiring 4a drawn out from one end of the high-resistance semiconductor layer 3 through a contact hole, and the high-resistance semiconductor layer 3
A metal wiring 4b is drawn out from the other end of the gate electrode 7 through a contact hole and connected to the gate electrode 7. Here, 5
is an interlayer insulating film as in FIG. In this way, the high-resistance semiconductor layer 3 including the gate electrode 7 changes the resistivity of the region in contact with the gate insulating film 6 due to the electric field effect caused by the voltage applied to both ends. This effect is effective for example at a thickness of 1500
In the case of a human polysilicon layer, the resistance value is so large that the resistance value can be increased to 10<12 >ohms/hole, which is about 10 times the resistance value of 2×10<11 >ohms/hole when no electric field effect is generated.

FIG. 2 is a sectional view of a high resistance region showing another embodiment of the present invention. According to this embodiment, a semiconductor substrate 1, a field insulating film 2 formed on one main surface of the semiconductor substrate 1, a semiconductor layer 8 of a conductivity type opposite to that of the semiconductor substrate 1, which is provided in the opening of the field insulating film 2 with its end in contact with the semiconductor substrate 1; A high-resistance semiconductor layer 3 formed so as to be in partial contact with the gate insulating film 6 and to extend over the field insulating VIA 2 with one end ohmically connected to the semiconductor layer 8; A metal wiring 4a is drawn out from the other end of the layer 3 through a contact hole.

According to this embodiment, the semiconductor layer 8 can achieve the same effect as the metal wiring 4b and the gate electrode 7 in the previous embodiment, and the high-resistance semiconductor layer directly above the gate insulating film 6 is caused by the electric field effect due to the voltage applied thereto. The resistivity of the layer can be changed significantly.

〔Effect of the invention〕

As explained in detail above, according to the present invention, the resistivity of a partial region of the high-resistance semiconductor layer can be controlled to have a large resistance value by the electric field effect caused by the wiring voltage. This has the effect of easily realizing a semiconductor device including a resistance region.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a high resistance region showing an embodiment of the present invention;
FIG. 2 is a sectional view of a high resistance region showing another embodiment of the present invention, and FIG. 3 is a sectional view of a high resistance region included in a conventional semiconductor device. DESCRIPTION OF SYMBOLS 1... Semiconductor substrate, 2... Field-insulating film, 3
...High resistance semiconductor layer, 4a, 4b...Metal wiring, 5
...Interlayer insulating film, 6...Gate insulating film, 7...Gate electrode, Agent Patent Attorney Uchihara Otokarasu 1st Edition 31iJ

Claims (1)

[Claims] a semiconductor substrate, a high-resistance semiconductor layer formed on one main surface of the semiconductor substrate via an insulating film, a wiring electrode that is ohmically connected to both ends of the high-resistance semiconductor layer, and one of the wiring electrodes. and a gate insulating film on the high-resistance semiconductor layer that is controlled by a potential.