JPS59181571A - Semiconductor device - Google Patents

Abstract

PURPOSE:To obtain the semiconductor device of electrode structure having an ohmic contact by a method wherein a high density impurity region is formed on the interfacial region of the semiconductor base layer which comes in contact with an electrode. CONSTITUTION:A contact compensation region 43 is formed on the electrode forming region located on the surface of a p type region 42 by selectively and shallowly introducing high density of boron into an n type silicon substrate 41. An insulating film 44, a titanium nitride layer 45, and an aluminum/silicon layer 46 are coated, and a wiring and an electrode having aluminum as the principal ingredient are formed by performing a patterning. When the boron density of the contact compensation boron containing region 43 is low, a voltage-current line has a non-linear form, which is non-ohmic contact in other words, but as the boron density becomes higher, said line is turned into a linear form, thereby enabling to obtain an ohmic contact.

Description

[Detailed description of the invention] (1) Technical field of the invention TECHNICAL FIELD The present invention relates to an electric power system, particularly to its electrical and direct structure.

(2) Prior Art and Problems Aluminum is generally used as an electrode material for semiconductor devices. FIG. 1 is an example of a normal electrode window. n
After forming a P shadow region 12 on a shaped silicon substrate 11 and covering it with an insulating layer 13, an electrode window is opened, and an electrode 1 is formed using aluminum.
form 4. Since aluminum sucks up silicon during the heat treatment of the Welly process, the interface 15 between aluminum (metal) and silicon (semiconductor) is deformed, causing penetration of the diffusion layer. For example, when the aluminum electrode 23 is in contact with a thin layered region like the p shadow region 22 in the n-type silicon substrate 21 in FIG.
A short-circuit between the n-shaded region 21 and the aluminum electrode 23, which is the lower layer of the through-hole 2, is likely to occur.

To avoid this situation, aluminum electrodes have conventionally been provided with a barrier to prevent silicon from being sucked up. Referring to FIG. 3, 3] is an n-type silicon substrate,
32 is a p shadow region, and 33 is an insulating film. The aluminum electrode has a three-layer structure, starting from the bottom: aluminum 1134 with a thickness of about 100 OX to form an ohmic contact with silicon, and TIN, for example, with a thickness of about 150 OX to prevent silicon from rising into the aluminum.

A barrier layer 35 such as ZrN + HfN * TaN,
Then, there is an aluminum layer 36 having a thickness of about 1 μn1, which forms the Ipt pole and the wiring body. That is, a nitride of a metal with a melting point such as TiN or aluminum is used as a barrier to prevent silicon from being absorbed. However, since the high melting point metal nitride has no ohmic contact with silicon, a thin layer of aluminum is used for direct contact with silicon.
The polar structure is not necessarily pure.

The above is an example of silicon siphoning from aluminum. (Also, the mutual or fusion of gold and gallium arsenide has the same problem.In that respect, nitrides of high melting point metals.)
At'
It is attractive as an electrode material. However, the question is whether the contact with the semiconductor is not ohmic.

(3) Purpose of the Invention In view of the current state of the prior art as described above, the present invention provides a semiconductor device 16 that has an electrode structure in which a hard nitride is brought into direct contact with a semiconductor and has an ohmic contact. The purpose is to

(4) Formation of the groove of the invention The present invention also provides for the formation of an air-contact inertia in the refitting of a semi-molar body made of a nitride of a high-melting point metal that is in contact with a semi-molar base. The above object is achieved by forming an impurity region of i concentration in the boundary region of the semiconductor base layer in contact with the electrode.

Incidentally, the melting point metals used here are titanium and tantalum.

This refers to tanksten, hafnium, molybdenum, norconium, niobium, pananium, chromium, etc.

Hereinafter, the invention will be made using 'Inuwari 1'.

(5) Embodiment of the Invention The following will be explained with reference to the fourth example. N-type silicon substrate (specific resistance ρ = 2 [Ω/cm)] By selectively introducing boron into 41, p-type head area (ρ, = 800 [Ω/mouth], depth CJ
im ], ρ = 20 [Ω/mouth]).
forming a contact compensation region 43 (diffusion);
Figure (a)). An insulating film 44 (for example, a silicon oxide film, a silicon oxide film, about 1 μm in thickness) is deposited to surround the pole window where '1≦'1 (FIG. 4 (b)).

Next, a titanium nitride layer 45 is coated (FIG. 4(c)).
Although an electrode may be formed using only this titanium nitride layer, for example, the single-layer titanium layer 45 is made to have a thickness of about 1500X, and the aluminum/silicon layer 46 is deposited on top of it and patterned. It is also possible to adopt a structure in which the main components are wiring and electrodes, and the suction of silicon is stopped by a titanium nitride film (see FIG. 4).

In order to examine the electrical contact between the electrodes created as described above and the silicon, two electrodes were placed in the same n-shaded area 42.
A voltage was applied between them as shown in Figure 5 (51 and 52 in Figure 5), and the current flowing through ylH2'L was investigated. The results are shown in FIG. 6, where the boron sensitivity of the contact compensation boron-containing region 43 is changed and the graph is plotted for each resistance value. As is clear from the figure, when the resistance value is low, that is, the elementary concentration is low, the voltage-current line is non-linear, that is, non-ohmic. I can see if it has become straight and ohmic.

Contact H4f Zeng Kai Fu; Other methods may be used to form the pure head area. For example, after forming an 11-shaped listening area 72 on a p-type silicon substrate 71, first, form an insulating film 733, Nitride techno film (about 1500X) 74
(ZK 7 (a)). I want to inject HOMET ions from above this 80 (kV)
, 5
500 [X]), a boron region 75 is formed at the bottom of the surface of the electrode forming region of the n-shaded region 72 by tracing the electrode window. After that, aluminum/silicon layer (thickness 1μ+f1
'4j) Limbs) Form 24 pairs and self glands in ' by twisting 76 and turning slightly.

Above, we have described a method for compensating electrical contact with a silicon base using titanium nitride as an example, and the present invention has described a method for compensating electrical contact with a silicon base layer using titanium nitride as an example. It will be clear to those skilled in the art that this is useful in contact compensation when contact is made.

(6) Effects of the Invention Secrets of 1 or more The point where the pL is touched and the ohmic contact is made.
Onizuro Semiconductor Devices will provide 64 pieces of equipment.

[Brief explanation of the drawing]

FIG.
The figure shows a part of a semi-double body with an aluminum body.
The top view and Figure 3 do not show aluminum with barrier metal.
FIG. Part H) [Top view, &T5 is a sectional view showing the test method of the real axis second semiconductor device 11) of the present invention,
FIG. 7 is a graph summarizing the irregularities of various parts of the 61st case, and FIG. 11.21.31.41.71 = n-type substrate, 12.2
2,32,42.72...p shadow area, 13°33,
44, 73... Insulating layer, 14, 23, 34° 36.
46.76...Aluminum J threat, 35,45°74
...su8! Natan/vy, 43+ 75...Contact I 111i ￥ High degree of boron implantation. Special J9 rank runner Fujino J stock martial arts summons patent issued, envyyono; Jinshuuji Shōki Roushōku Nishi wata Kazunozui: Assassin 1) ￥ Otokobenkonshi Yamaguchi 1. f3 No. 1 Figure 1'+ Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 1 Moon- Figure 7 (A) 5 (C)

Claims (1)

[Claims] 1. Semiconductor, l! A semiconductor characterized in that it has an electrode made of a nitride of a high melting point metal in contact with the semiconductor base layer, and a high concentration impurity region for electrical contact compensation is provided in an interface region of the semiconductor base layer that contacts the electrode. Device.