JPS6155938A - Method for isoration of electronic element - Google Patents

Abstract

PURPOSE:To isolate electronic elements easily without extending the intervals by forming the isolation zones of electronic elements out of the layer including a deep trap level produced by impurities or defects existing in the semiconductor substrate. CONSTITUTION:By chemical etching of a highly-resistant semiconductor substrate 30, a layer including a deep trap layer is formed in the vicinity of the surface of substrate 30. Nextly, by etching only the surface where barrier junction electrodes 1 are formed by Ar<+> ions, the layer including a deep trap level is removed and the layer including a deep trap level is left in the part except the plane on which the electrodes 1 are formed thereby forming isolation zones 10. After forming the isolation zones 10, the electrodes 1 are formed by Schottky barrier junction in the part where the deep trap level is removed and the electrodes composed electronic elements together with an ohmic electrode 2 formed in another plane.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to improvement of isolation characteristics between a plurality of electronic elements formed on a semiconductor substrate by a pn junction, a Schottky barrier junction, or the like.

<Prior Art> When forming a thin film on the semiconductor L4 board to form electronic elements such as diodes and transistors, it is economically advantageous to form as many electronic elements as possible in a small area.

Conventionally, as a method for forming electronic elements on a semiconductor substrate,
What is shown in cross-sectional views in FIGS. 2 to 4 is known.

In Fig. 2, reference numeral 3 denotes a semiconductor substrate, on one side of which Schottky barrier junctions rPi(il) are formed at a constant interval d, and on the other side, an ohmic junction Fi pole 2 is formed over the entire surface, and Iyl power distribution. (Electronic elements are configured between 1° and 2 mm.) In the conventional example described above, the separation between each electronic element is achieved by using the semiconductor substrate 3 as a high-resistance semiconductor and keeping a large distance between each electronic element. In such a structure, as shown in the cross-sectional view of Fig. 5, even if an attempt is made to increase the resistance of the semiconductor substrate to form an electronic element with a high a-density, As the carrier m degree of the resistive semiconductor decreases, the depletion FI8 expands, and this depletion 1!!78 comes into contact with adjacent electronic elements, making it difficult to reduce the distance between each electronic element, which is economically disadvantageous. There is also a problem with the arrangement of each electronic element.

In the conventional example shown in FIG. 3, an epitaxial layer 4 is formed on one surface of a semiconductor substrate 3, and an epitaxial layer F'J4 is etched on this layer after Schmittsky barrier bonding to separate each electronic element. This is a method of forming an electronic element between the ohmic electrode 2 formed on the other surface of the semiconductor substrate, but the technique of forming an epitaxial layer on a semiconductor substrate and performing mesa etching on its surface is the most common method for each cured compound semiconductor. It is not well established and is often introductory.

In the conventional example shown in FIG. 4, an epitaxial layer VI4 is formed on one surface of a semiconductor substrate 3, and this epitaxial layer ll! 1
4 is separated by a diffusion film 15 and an ohmic electrode 2 formed on the other surface forms an electronic device. For example, if the epitaxial layer is a 0-type epitaxial layer, the diffusion layer is formed as a p+ diffusion layer. . In this case, the Schottky barrier junction electrode 1 may be formed before or after the diffusion layer 5 is formed.

However, the heat treatment process and dopant selection for forming diffusion 1!15 in various compound semiconductors are not technically established and are often difficult.

<Object of the invention> The present invention has been made in view of the problems of the above-mentioned conventional example.
It is an object of the present invention to provide a separation method that allows easy separation without increasing the space between electronic elements.

<M4 configuration of the invention> The configuration of the present invention that achieves this objective is to
In a method for separating electronic devices when a plurality of electronic devices are formed using n-junctions or Schottky barrier junctions, etc., the separation band of the electronic device is formed into a layer containing deep trap units caused by defects and impurities existing in the semiconductor substrate. Its structural feature is that it is formed by.

<Embodiment> FIG. 1 shows an embodiment of the present invention, in which 30 is a high-resistance semiconductor made of, for example, a p-type CdTe crystal. 10
is a separation band, which is formed by a layer containing deep trap units caused by defects and impurities formed on the surface of the high-resistance semiconductor 30. This defect, li!, contains deep trap units caused by impurities! Normally, the defects 110 should be removed as much as possible as defects in the semiconductor substrate, but in the present invention, this defect is actively utilized to form the separation zone 10. First, the high-resistance semiconductor substrate 30 is chemically etched to form a layer containing deep trap units near the surface of the substrate 30, and then only the portion where the Schottky barrier junction W1 pole 1 is formed is etched with Ar+ ions. Then, the layer containing the deep trap order is removed, and the layer containing the deep 1-lap order is left on the surface other than the surface where the Schottky barrier junction electrode 1 is formed, and a layer m (l) 10 is formed. A1. Pt
A Schottky filter is applied to the part where the deep trap level is removed.
An electrode 1 is formed by barrier bonding, and together with an ohmic electrode 2 formed on the other surface, an electronic element is constructed.

According to this method, the expansion of the depletion layer formed in the semiconductor substrate 30 by the Schottky barrier junction is prevented by the separation band 10, and the adjacent electronic elements do not come into contact 71.

Assuming that an electronic device is formed on a half-half board, C is
Various uses are possible, such as a photodetection element, a β-ray detection element, a χFA detection channel type, and a -C formation. Further, in this embodiment, one electrode constituting the electronic element is described as a Schottky barrier junction electrode, but this electrode may also be constructed as a pH junction electrode.

<Effects of the Invention> As explained above in conjunction with the embodiments, according to the present invention, a separation zone can be formed by an in-house method, and electronic elements can be formed in a high density on a semiconductor. The economic effect is great.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a cross-sectional view of a semiconductor substrate showing an embodiment of the present invention;
2 to 4 are cross-sectional views of a semiconductor substrate showing a conventional example, and FIG. 5 is a cross-sectional view showing a state in which the depletion layers are in contact with each other in the conventional example of FIG. 1... Schottky barrier electrode, 2... Ohmic junction electrode, 10... Separation band, 30... High (■Antibiotic conductor.

Claims (1)

[Claims] In a method for separating electronic devices when a plurality of electronic devices are formed on a semiconductor substrate using pn junctions or Schottky barrier junctions, separation bands of the electronic devices are separated into deep trap states caused by defects and impurities existing in the semiconductor substrate. 1. A method for separating an electronic device, characterized in that the electronic device is formed by a layer containing an active layer.