JPH0366137A - Manufacture of metal semiconductor junction - Google Patents

Abstract

PURPOSE:To eliminate a need for a developing treatment of a resist layer and to easily manufacture a metal semiconductor junction element by a method wherein, while a metal compound gas is being supplied, a window for metal- layer installation use is irradiated with a focused ion beam and a metal layer which forms a metal semiconductor junction between itself and a semiconductor substrate or a semiconductor layer is deposited and formed. CONSTITUTION:Before a metal layer 18 which forms a metal semiconductor junction 17 between itself and a semiconductor substrate 1 is formed, a thin film 11 is formed on the semiconductor substrate 1 and a window 13 for metal- layer installation use is formed in the thin film 11. The metal layer 18 can be formed only when a prescribed region 16 on the semiconductor substrate 1 is irradiated with a focused ion beam while a metal compound gas is being supplied to the prescribed region 16 on the semiconductor substrate 1. When the window 13 for metal-layer installation use is formed, the focused ion beam is used not for an exposure treatment of a resist layer but for an etching treatment of the thin film 11. Consequently, a developing treatment of the resist layer is not required.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a method for manufacturing a metal-semiconductor junction element in which a semiconductor substrate or a semiconductor layer and a metal layer disposed thereon forming a metal-semiconductor junction therebetween.

[Conventional technology]

Conventionally, a metal-semiconductor junction element having a semiconductor substrate or a semiconductor layer and a metal layer disposed on the semiconductor substrate to form a metal-semiconductor junction thereon has been conventionally used as a semiconductor substrate or a semiconductor layer.Secondly, a resist layer is used. (1) Next, a process of forming a window for disposing a metal layer on the resist layer by exposure treatment using a focused ion beam on the resist layer and subsequent development treatment; (2) Next, a process of forming a window for disposing a metal layer on the resist layer; Alternatively, on the semiconductor layer, an unpatterned metal layer extending continuously on the resist layer and into the metal layer disposing window is subjected to an Ifi forming acid forming process; By etching the unpatterned metal layer using a mask, the unpatterned metal layer is etched onto the semiconductor substrate or semiconductor layer in the area facing the metal layer placement window. A method for manufacturing a metal-semiconductor bonding element comprising the step of forming a patterned metal layer forming a metal-semiconductor bond as a metal layer of a metal-semiconductor bonding element (this method is performed using a conventional first metal layer). A method for manufacturing a semiconductor junction device) has been proposed. Conventionally, the above-mentioned metal-semiconductor junction element has been prepared by: (i) supplying a metal compound gas to a predetermined region on the semiconductor substrate or semiconductor layer, and moving a predetermined region on the semiconductor substrate or semiconductor layer forward with a focused ion beam; A metal-semiconductor junction element manufactured by a process of depositing a metal layer forming a metal-semiconductor junction with a semiconductor substrate or semiconductor layer in a predetermined region on a semiconductor substrate or semiconductor layer. A manufacturing method (this will be referred to as a conventional second metal-semiconductor junction device manufacturing method) has also been proposed.

[Problem to be solved by the invention]

According to the above-described first conventional method for manufacturing a metal-semiconductor bonding element, the metal-semiconductor bond formed between the semiconductor substrate or the semiconductor layer and the metal layer has the same dimensions as the metal layer disposing window of the resist layer. can be formed with. Incidentally, the window for metal layer arrangement in the resist layer is formed by exposure processing using a focused ion beam followed by development processing, but in this case, the focused ion beam is Since it can be obtained as a metal layer, the window for disposing the metal layer can be formed to have a sufficiently narrow width of 0.1 μm or less. Therefore, according to the above-described first conventional method for manufacturing a metal-semiconductor junction element, the metal-semiconductor junction formed between the semiconductor U plate or the semiconductor layer and the metal layer can be formed with a thickness of 0.1 μm or less. It can be formed with a narrow width, and thus the metal-semiconductor junction element can be manufactured in a compact and dense manner. However, in the case of the above-mentioned first conventional method for manufacturing a metal semiconductor junction element, a process of exposing the resist layer using a focused ion beam in order to form a window for metal layer arrangement in the resist layer, followed by development. The metal layer (
a step of depositing an unpatterned metal layer on a semiconductor substrate or a semiconductor layer to form a patterned metal layer; and etching the unpatterned metal layer. This method requires many steps, and therefore has the disadvantage that metal semiconductor junction devices cannot be easily manufactured with a high yield. Further, according to the above-described second conventional method for manufacturing a metal-semiconductor bonding element, a metal layer forming a metal-semiconductor bond with a semiconductor substrate or a semiconductor layer is placed in a predetermined area on the semiconductor substrate or semiconductor layer. The metal-semiconductor junction element can be easily formed by simply irradiating a predetermined region on the semiconductor substrate or semiconductor layer with a focused ion beam while supplying a metal compound gas to the metal-semiconductor junction element.
This method can be manufactured more easily than the manufacturing method of the metal semiconductor junction element. However, in the case of the above-mentioned conventional method for manufacturing the second metal-semiconductor junction element, when the metal layer forming the metal-semiconductor junction with the semiconductor substrate or semiconductor layer is deposited using a focused ion beam, Since the semiconductor substrate or semiconductor layer is exposed to the outside even around the intended area, even if the focused ion beam is irradiated only to the intended area of the semiconductor substrate or semiconductor layer, the metal layer It is formed on a semiconductor substrate or a semiconductor layer to occupy a larger area than the intended area that includes the intended area. Therefore, assuming that a focused ion beam can be obtained with a small diameter of 0.1 μm or less, a metal-semiconductor junction can be formed with a sufficiently narrow width of 0.1 μm or less. I can't do it,
Therefore, the metal semiconductor junction device has a disadvantage in that it is not possible to precisely manufacture the metal semiconductor junction element in a small size. Furthermore, when forming a metal layer that forms a metal-semiconductor junction with a semiconductor substrate or semiconductor layer, as described in 2. When a metal layer is formed, the same metal particles that make up the metal layer may be exposed to the semiconductor sheet or the area around the metal layer on the semiconductor layer. Direct deposition in amounts that do not result in adhesion and therefore
The top surface of the semiconductor substrate or semiconductor layer is directly contaminated by metal particles. For this reason, after forming a metal layer forming a metal semiconductor junction with a semiconductor substrate or semiconductor layer, unless the metal particles are removed from the semiconductor sheet or the semiconductor layer, the metal semiconductor junction element cannot be used. , the metal particles cannot be manufactured with the desired characteristics, and therefore, if an attempt is made to remove the metal particles from the semiconductor substrate or the semiconductor layer, the semiconductor substrate or the semiconductor layer will be damaged; Therefore, in any case, the drawback is that a metal-semiconductor junction element cannot be manufactured with desired characteristics. Therefore, the present invention seeks to propose a novel metal-semiconductor junction device that does not have the above-mentioned drawbacks.

[Means to solve the problem]

The method for manufacturing a metal-semiconductor junction device according to the first invention of the present application consists of (1) forming one or more thin films on a semiconductor single plate or a semiconductor layer, and (2) etching each thin film using a focused ion beam. , forming a metal layer disposing window in the thin film that exposes the semiconductor substrate or semiconductor layer to the outside, and (ii) disposing the metal layer while supplying a metal compound gas into the metal layer disposing window. In order to irradiate the window for metal layer with a focused ion beam, a layer d3 is placed on the semiconductor sheet or semiconductor layer in a region facing the window for metal layer arrangement, and between it and the semiconductor substrate or semiconductor layer. The process of depositing a metal layer forming a metal-semiconductor junction is described below. In addition, in the method for manufacturing a metal semiconductor junction element according to the second invention of the present application, in the method of manufacturing a metal semiconductor junction element according to the first invention of the application, after the step of depositing the metal layer, at least the first two layers of the thin film are formed. The process of removing the layer is described below.

[Action/effect]

According to the method for manufacturing a metal-semiconductor bonding element according to the first invention of the present application, a metal layer forming a metal-semiconductor bond with a semiconductor substrate or a semiconductor layer is formed as shown in I). By removing the step of forming a thin film on the layer and the step of forming a window for disposing the metal layer in the thin film, the metal layer forming the metal-semiconductor junction with the semiconductor substrate or semiconductor layer can be removed. Similarly to the method for manufacturing the second conventional metal-semiconductor junction element described above, a predetermined region on the semiconductor substrate or semiconductor layer is supplied to the predetermined region on the semiconductor substrate or semiconductor layer while supplying the metal compound gas to the predetermined region on the semiconductor substrate or semiconductor layer. It can be formed simply by irradiation with a focused ion beam, and in order to form a window for disposing a metal layer in a thin film, as in the case of the above-mentioned conventional method for manufacturing the first metal-semiconductor junction element,
A focused ion beam is used, and the focused ion beam is used for the exposure treatment on the resist layer as in the case of the first conventional method for manufacturing the metal semiconductor junction element described above. It is used for processing,
Therefore, unlike the above-mentioned first conventional manufacturing method of the metal-semiconductor junction element, there is no need to develop the resist 1 to the layers, so that the metal-semiconductor junction element can be manufactured using the conventional first method JDS21' conductor]. It can be produced much more easily than in the case of the method for producing gougers. Further, according to the method for manufacturing a metal-semiconductor junction element according to the first invention of the present application, the metal layer forming the metal-semiconductor junction with the semiconductor substrate or the semiconductor layer, as described above,
As in the case of the manufacturing method of the second conventional metal-semiconductor junction element described above, a predetermined region of the semiconductor substrate or semiconductor layer is covered with focused ions while a metal compound gas is supplied onto the predetermined region of the semiconductor substrate or semiconductor layer. When irradiated with a beam), the semiconductor substrate or semiconductor layer is exposed to the outside only in the region facing the thin film metal layer disposing window, and that region is exposed to the outside of the semiconductor substrate or semiconductor layer. This is a predetermined area. For this reason, a metal layer can be formed on a semiconductor substrate or a semiconductor layer occupying only a predetermined area having a predetermined area, and thus a metal-semiconductor junction can be used for disposing a thin metal layer. It can be formed with the same dimensions as the window. Incidentally, the window for disposing a thin film metal layer is formed using a focused ion beam in accordance with the first conventional method for manufacturing a metal-semiconductor junction element described above. In the case of the manufacturing method for metal semiconductor bonding devices, as mentioned above, it is possible to obtain a focused ion beam with a diameter as small as 0.1 μm or less. It can be formed to have a sufficiently narrow width. Therefore, the metal-semiconductor junction formed between the semiconductor substrate or the semiconductor layer and the metal layer can be formed to have a sufficiently narrow width of 0.1 μm or less. The metal-semiconductor junction element can be manufactured compactly and densely without having the disadvantages of the second method of manufacturing the metal-semiconductor junction element. Further, according to the method for manufacturing a metal-semiconductor junction element according to the first invention of the present application, when forming a metal layer forming a metal-semiconductor junction with a semiconductor substrate or a semiconductor layer, as described above, the semiconductor Since the substrate or semiconductor layer is exposed to the outside only in the region facing the thin film metal layer forming window, that region is designated as the Schedule 1 region. Even if the same metal particles deposited on the thin film are not deposited directly on the semiconductor substrate or semiconductor layer, the top surface of the semiconductor substrate or semiconductor layer is not directly contaminated by the metal particles. Therefore, after forming a metal layer forming a metal-semiconductor junction with a semiconductor substrate or semiconductor layer, the metal-semiconductor junction element can be formed without removing metal particles from the semiconductor substrate or semiconductor layer. , can be manufactured with almost any desired properties. Further, according to the method for manufacturing a metal-semiconductor junction element according to the second invention of the present application, in the step of depositing a metal layer forming a metal-semiconductor junction with a semiconductor substrate or a semiconductor layer, a thin film is formed as described above. Even if metal particles are deposited on top, the metal particles can be removed by removing at least the top layer of the thin film. If there is a possibility that the product cannot be manufactured as having
In addition, at least the top layer of the thin film formed on the semiconductor substrate or semiconductor layer is
J: When removing metal particles deposited directly on a semiconductor substrate or semiconductor layer: It can be easily removed from the semiconductor substrate or semiconductor layer without damaging the semiconductor substrate or semiconductor layer. , a metal-semiconductor junction device having desired characteristics can be easily manufactured.

【Example】

Next, an embodiment of the method for manufacturing a metal-semiconductor junction element according to the present invention will be described with reference to FIGS. 1 to 8. The method for manufacturing a metal semiconductor junction element according to the present invention shown in FIGS. 1 to 8 includes the following sequential steps. That is, a semi-insulating semiconductor 1 board 1 made of, for example, GaAS"CI' is prepared in advance (FIGS. 1A and B). Then, in the semiconductor substrate 1, for example, an n+ type semiconductor is formed on the main surface 1a side. Two semiconductor regions 2 and 3 each having a width of, for example, about 8 μm are formed by an n-type impurity introduction process which is known per se, with an inner spacing of, for example, P μm, and then or before that, the semiconductor regions 2 and 3 are formed with a width of about 8 μm. a semiconductor region 2 with an n-type extending between 2 and 3;
and a semiconductor region 4 having a width slightly narrower than 3;
Similarly, n, which is known per se, is formed by an impurity introduction process (FIGS. 2A and B). Next, windows 6 and γ are provided on the main surface 1a of the semiconductor substrate 1, and windows 6 and γ are provided to view the semiconductor regions 2 and 3 to the outside, respectively.
An insulating layer 5 made of iO, Si3N4, etc. is formed to a thickness of, for example, 1,500 mm using various methods known per se, such as plasma CVD (FIGS. 3A and 3B). Next, conductive layers 8 and 9 made of a layered material such as an AuGeN i alloy layer or an Au layer are applied ohmically to the semiconductor regions 2 and 3 in the regions facing the windows 6 and 7 of the respective insulating layers 5. are formed by various methods known per se, with windows 6 and 7, respectively, completely filled (FIGS. 4A and 4B). Next, on the insulating layer 5, a layer 10 is formed to cover and extend the conductive layers 8 and 9, and to have a thickness of, for example, iooo. (5th
Figures A and B). Next, the thin film 11 consisting of the insulating layer 5 and the layer 10 is irradiated with a focused ion beam 12 of Ga ions accelerated at, for example, 30 KeV and having a controlled current density for a controlled period of time. By etching the thin film 11 using a focused ion beam 12, the semiconductor substrate 1 may be etched with a semiconductor region 4 between the semiconductor regions 2 and 3 having a width of, for example, 0.1 μm and a length of, for example, 10 μm. In the striped region 16 extending across the striped region 5, a striped window 13 for disposing a metal layer facing the outside is formed (FIGS. 6A and B). For example, W(
While supplying the metal compound gas 14 consisting of CO〉6,
The focused ion beam 12 is accelerated to, for example, 30 KV in an atmosphere having a metal compound gas pressure of 10-5 torr, and is used to form the metal layer forming window 13 on the thin film 11. By sweeping the front side with a focused ion beam 15 of Qa ions having a controlled current density lower than that of the semiconductor substrate 1, a region 16 facing the metal layer disposing window 13 is formed on the semiconductor substrate 1. A metal layer 18 made of W, which forms a metal-semiconductor junction 17 therebetween, is formed in a #1 stack in such a manner that it completely fills the window 13 for metal layer arrangement and traverses the semiconductor region 4 (FIG. 7). A and B>. In this case, the metal layer 18 extends slightly onto the thin film 11 and is formed in the shape of a mushroom. Next, a thermal annealing treatment is performed at a temperature of 150°C to 500°C, and then the thin film is The layer 10, which is the uppermost layer 6 of 11, is removed (FIGS. 8A and B). The above is an embodiment of the method for manufacturing a metal semiconductor junction element according to the present invention.A metal semiconductor junction manufactured by such a manufacturing method The device includes semiconductor regions 2 and 3 as source and drain regions, semiconductor region 4 as a channel region, and conductive layer 8.
and 9 are the source electrode and drain electrode, respectively, and the metal layer 18 is the gate electrode.
It is clear that the structure has the structure of a transistor, and therefore the function as a transistor can be obtained. Therefore, the method of manufacturing a metal semiconductor junction device according to the present invention shown in FIGS. 1 to 8 can be said to be a manufacturing method applied to an embodiment of the method of manufacturing a Schottky junction field effect transistor. According to the method for manufacturing a metal-semiconductor bonding device according to the present invention shown in FIGS. Fifth
), a step of forming a metal layer disposing window 13 in the thin film 11 through which the semiconductor substrate 1 is exposed to the outside by etching the thin film 11 using a focused ion beam 12 (FIG. 6); Metal compound gas 14 inside the installation window 13
By irradiating the window 13 for metal layer arrangement with the focused ion beam 15 while supplying The process includes a step of depositing a metal layer 18 forming a semiconductor junction 17 (FIG. 7), and a step of removing the layer 10 which is the uppermost layer of the thin film 11 after that step (FIG. 8). According to the method for manufacturing a metal-semiconductor bonded device according to the present invention, before forming the metal layer 18 forming the metal-semiconductor bond 17 with the semiconductor substrate 1. As long as the process of forming a thin film 11 on the semiconductor substrate 1 (FIGS. 3 and 5) and the process of forming the window 13 for metal layer arrangement on the thin film 11 (FIG. 6) are performed, The metal layer 18 forming the metal-semiconductor junction 17 with the semiconductor substrate 1 is placed in a predetermined region 16 on the semiconductor substrate 1, as in the case of the conventional second metal-semiconductor junction element manufacturing method described above. The metal layer can be formed by simply irradiating a predetermined region 16 on the semiconductor substrate 1 with the focused ion beam 15 while supplying the metal compound gas 14, and the metal layer forming window 13 can be formed in the thin film 11. In this method, the focused ion beam 12 is used as in the case of the conventional method for manufacturing the first metal semiconductor junction element described above, but the focused ion beam 12 is It is not used for the exposure process on the resist layer as in the case of the conventional method, but is used for the etching process to inscribe the thin film 11. Therefore, unlike the above-mentioned conventional method for manufacturing the first metal-semiconductor bonding element, the resist layer is not developed. Since no processing is required, the metal semiconductor junction element can be manufactured much more easily than in the case of the conventional first metal semiconductor junction element manufacturing method described above. According to the method for manufacturing a metal semiconductor junction element according to the present invention shown in FIG. As in the case of the manufacturing method of the metal-semiconductor junction device in No. 2, the predetermined region 1 of the semiconductor substrate 1
The semiconductor substrate 1 is formed by irradiating a predetermined region 16 of the semiconductor substrate 1 with a focused ion beam 15 while supplying a metal compound gas 14 onto the semiconductor substrate 1.
is exposed to the outside only in a region 16 of the thin film 11 facing the metal layer arrangement window 13, and that region 16 is defined as a predetermined region 16 of the semiconductor substrate 1. For this reason, the metal layer 18 can be formed on the semiconductor substrate 1 so as to occupy only a predetermined area 16 having a predetermined area, and thus the metal semiconductor junction 17 can be formed in the metal layer arrangement of the thin film 11. It can be formed with the same dimensions as the installation window 13. By the way, the metal layer arrangement window 13 of 1ill1311 is formed using a focused ion beam according to the method for manufacturing the first conventional metal semiconductor junction element described above. As mentioned above in the case of the method for manufacturing a metal semiconductor junction element in No. 1, since a focused ion beam can be obtained with a diameter as small as 0°1 μm or less, the intermetallic arrangement window 13 is It can be formed to have a sufficiently narrow width of 0.1 μm or less. Therefore, the metal-semiconductor junction 17 formed between the semiconductor substrate 1 and the metal layer 18 can be formed to have a sufficiently narrow width of 0°1 μm or less. The metal-semiconductor junction element can be manufactured compactly and densely without having the disadvantages of the second method of manufacturing the metal-semiconductor junction element. Further, according to the method for manufacturing a metal semiconductor junction element according to the present invention shown in FIGS. 1 to 8, when forming the metal layer 18 forming the metal semiconductor junction 17 with the semiconductor substrate 1, the above-mentioned As described above, the semiconductor substrate 1 is only in the region 16 facing the metal layer disposing window 13 of the thin film 11.
6 is exposed to the outside as a predetermined area, so when forming the metal layer 18, the same metal particles 19 that make up the metal layer 18 are deposited on the thin film 11 as shown in the figure. 1
Even if metal particles 19 are deposited on the semiconductor substrate 1, the upper surface of the semiconductor substrate 1 is not directly deposited on the semiconductor single substrate 1.
not be directly contaminated by Therefore, according to the metal-semiconductor junction device according to the present invention shown in FIGS. 1 to 8, after forming the metal layer 18 forming the metal-semiconductor junction 17 between the semiconductor substrates 1, Although metal particles 19 are removed by removing layer 10, which is the top layer of thin film 11, metal-semiconductor junctions do not require removing metal particles 19 from the semiconductor substrate or semiconductor layer in this way. Elements can already be manufactured with desired characteristics. Further, according to the method of manufacturing a metal semiconductor junction element according to the present invention shown in FIGS. 1 to 8, there is a step of forming an Mt layer 18 forming a metal semiconductor junction 17 with the semiconductor substrate 1. One metal particle attached to the thin film is removed by removing layer 10, which is the top layer of thin film 11, so unless metal particle 19 is removed, the metal semiconductor junction will not be formed. What is the desired characteristic of the element? If there is a possibility that it will not be possible to manufacture the semiconductor substrate 1, this further risk can be effectively avoided. The layer 10, which is the top layer of the thin film 11 that is present on the semiconductor substrate 1, is capable of depositing f[ff v4 on the semiconductor substrate 1 without damaging the semiconductor substrate 1, as would be the case with metal particles that are directly deposited on the semiconductor substrate 1. C′, which can be easily removed from above, allows the metal-semiconductor junction device to be easily manufactured as a material with the desired characteristics. This is merely an example of the method for manufacturing a metal-semiconductor junction device according to the present invention when applied to the method for manufacturing an effect transistor, and the method for manufacturing a metal-semiconductor junction device according to the present invention is only one embodiment of the method for manufacturing a metal-semiconductor junction device according to the present invention.
The present invention can also be applied to the manufacturing method of a HEMT type field effect transistor having a structure in which a metal-semiconductor junction is formed between a body layer and a metal layer. Various modifications and changes may be made without departing from the spirit of the invention.

[Brief explanation of drawings]

1st drawing and B-8th drawing and B (Fig.・・・・・・・・・・・・Semiconductor odor plate 2.3.
4... Semiconductor region 5... Insulating layer 6.7...
. . . Window 8.9 . . . Conductive layer 11 . . . L layer 12 .
......Focused ion beam 13...
......Window 14 for metal layer arrangement...
・・・・・・・・・Metal compound gas 15・・・・・・
......Focused ion beam 16...
・・・・・・・・・Area 4

Claims (1)

[Claims] 1. Forming one or more thin films on a semiconductor substrate or a semiconductor layer, and etching the thin film using a focused ion beam to form the semiconductor substrate or semiconductor on the thin film. forming a window for metal layer placement that exposes the layer to the outside; and irradiating the window for metal layer placement with a focused ion beam while supplying a metal compound gas into the window for metal layer placement. Accordingly, on the semiconductor substrate or the semiconductor layer, in a region facing the metal layer arrangement window,
A method for manufacturing a metal-semiconductor junction element, comprising the step of depositing a metal layer forming a metal-semiconductor junction with the semiconductor substrate or semiconductor layer. 2. The method for manufacturing a metal-semiconductor bonding element according to claim 1, further comprising the step of removing at least the uppermost layer of the thin film after the step of depositing the metal layer. Element manufacturing method.