JPS6352790B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a Hall element that allows mass production of substantially cross-shaped magnetically sensitive parts with little variation in characteristics.

Conventionally, when manufacturing a Hall element, a protective insulating layer of SiO ₂ , Al ₂ O ₃ , etc. was first formed on a ferrite, glass, ceramic plate, etc. to prevent impurities from entering, as shown in Figure 1. A substrate 1 is prepared, a semiconductor film such as InSb is formed on the entire main surface of the substrate 1 by vapor deposition, and heat treatment is performed for crystallization. Next, a substantially cross-shaped magnetic sensing portion 2 as shown in FIG. 1 is formed by photoetching so that there is no variation in characteristics. Next, after removing the oxide film on the surface of the magnetically sensitive part 2, as shown in FIG. The electrode metal layer 3 is formed by depositing an electrode material selected from the following. Thereafter, the electrode metal layer 3 is selectively removed by photoetching as shown in FIG.
the first, second, connected to a, 2b, 2c, 2d;
Third and fourth electrodes 3a, 3b, 3c, and 3d are formed to form a Hall element chip.

By the way, a cross-shaped magnetic sensing part 2 is formed by selectively depositing a semiconductor material using a mask as shown in FIG.
However, since the magnetically sensitive part 2 is extremely small, e.g. 0.7 to 1.0 mm in length and 0.3 to 0.5 mm in width, it is difficult to mass-produce elements with little variation in characteristics by mask vapor deposition. It is. Therefore,
Conventionally, the magnetic sensitive part 2 was created using a highly accurate photoetching method.
was formed. However, in the conventional manufacturing method, two etching steps are required to obtain the magnetically sensitive portion 2 and the electrodes 3a to 3d, and each etching step includes resist coating, prebake, exposure, development, postbake, Etching, cleaning, resist stripping, cleaning, etc. were required, which inevitably required a large number of workers. Furthermore, even if the photo-etching pattern is the same, when multiple Hall elements are formed at the same time for mass production, there will be variations in the semiconductor thin film and the oxide film produced during heat treatment, resulting in variations in the characteristics of the completed Hall elements. did.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method for manufacturing a Hall element that can easily obtain a Hall element with less variation in characteristics.

To achieve the above object, the present invention selectively applies a semiconductor material such as InSb or InAs to an approximately central region of a substrate including a semiconductor film forming region necessary for forming a Hall element using a mask. A step of forming a Hall effect semiconductor film by depositing the semiconductor film, and using a mask that deposits on the electrode connection portion of the semiconductor film but not on the magnetically sensitive part of the semiconductor film, for example, Cr, Ti, Au, Cu, Ag, Ni
A process of selectively depositing a conductive material such as the like to form four independent lead-out electrodes, and forming the boundary between the necessary and unnecessary parts of the semiconductor film into a linear shape by heating or cutting with a laser beam, etc. The present invention relates to a method for manufacturing a Hall element, comprising the steps of: forming a substantially cross-shaped magnetically sensitive portion by removing and providing a groove.

According to the present invention, the Hall element is formed by a combination of a technique of selectively forming an adhesion layer using a mask and a technique of non-chemically forming linear grooves, so that photo This eliminates the need for an etching process, making it possible to significantly improve productivity.
Furthermore, since trimming can be performed at the same time as groove formation, variations in characteristics can be reduced and yield can be improved.

Embodiments of the present invention will be described below with reference to FIGS. 4 to 7.

As shown in FIG. 7, a substrate 1 consisting of a ferrite substrate 1a and a protective insulating layer 1b is prepared, and a substantially central region of the upper surface 4 of the substrate 1, which includes a semiconductor film formation region necessary for forming a Hall element, is prepared. Using a mask, InSb is selectively deposited and heated to form a crystallized Hall effect semiconductor film 5 as shown in FIG. The pattern of this semiconductor film 5 only needs to have a shape that includes a magnetically sensitive part that will ultimately be formed in a cross shape, so almost no precision is required. It should be formed as follows. In mass production, in order to simultaneously form a plurality of Hall elements, a plurality of semiconductor films 5 are simultaneously formed on independent or common substrates.

Next, using a mask, for example, Cr and Ag are sequentially deposited as conductive materials for forming electrodes, thereby forming the first, second, third and fourth electrodes 3a and 3 shown in FIG.
Form b, 3c, and 3d. Note that the electrodes 3a to 3d are formed so that a portion thereof overlaps with the electrode connection portions 2a to 2d of the semiconductor film 5. In addition, each electrode 3a to 3
It is formed so that a separation part 6 is formed between d.

Next, power 1~3W, speed 50mm/sec,
By projecting a laser beam onto the semiconductor film 5 and heating it so that the line width is about 30 to 50μ,
As shown in FIG. 6, a specific pattern of linear grooves 7 is provided in the semiconductor film 5. This groove 7 is formed so that a cross-shaped magnetic sensing part 2 is generated and is automatically formed by computer programming to perform trimming for resistance adjustment and unbalanced voltage adjustment. If the groove 7 is formed at the boundary between the magnetically sensitive part 2, that is, the necessary part, and the unnecessary part 8 unrelated to the magnetically sensitive part 2, even if the unnecessary part 8 remains on the substrate 1, it can be electrically Not a hindrance at all.

As is clear from the above, according to this example,
The semiconductor film 5 and the electrodes 3a to 3d are vapor-deposited using a mask, and then the grooves 7 are formed using a laser beam to form the cross-shaped magnetically sensitive part 2, eliminating the need for photoetching and reducing productivity by 3 to 6. It is possible to double the improvement.

Moreover, since it is possible to perform trimming to correct unbalanced voltage, resistance value, etc. at the same time when forming the groove 7, it is possible to easily improve the yield.

Further, by vapor depositing the semiconductor film 5 with a mask, only a part of it exists under the electrodes 3a to 3d, so that the substrate 1 of the electrodes 3a to 3d
High adhesive strength against.

Although the embodiments of the present invention have been described above, the present invention is not limited thereto and can be further modified. For example, the substrate 1 may be made of ceramic, glass, or the like, provided with a protective insulating layer of Al ₂ O ₃ , SiO ₂ , glass, or the like.

[Brief explanation of drawings]

FIGS. 1, 2, and 3 are plan views showing a conventional Hall element in order of process, and FIGS. 4, 5, and 6 show a Hall element according to an embodiment of the present invention in order of process. The plan view, FIG. 7, is a sectional view taken along the - line in FIG. 6. In the symbols used in the drawings, 1 is the substrate, 2 is the magnetic sensing part, 2a to 2d are the connection parts, 3a to 3d are the electrodes, 5 is the semiconductor film, 7 is the groove, and 8 is an unnecessary part. .

Claims (1)

[Claims] 1. A Hall effect semiconductor film is formed by selectively depositing a semiconductor material on a substantially central region of a substrate including a semiconductor film forming region necessary for forming a Hall element using a mask. and forming four independent drawers by selectively depositing a conductive material using a mask that deposits the conductive material on the electrode connection portion of the semiconductor film but not on the magnetically sensitive portion of the semiconductor film. a step of forming an electrode; and a step of forming a substantially cross-shaped magnetically sensitive portion by linearly removing a boundary portion between a necessary portion and an unnecessary portion of the semiconductor film by heat or cutting to provide a groove. A method for manufacturing a Hall element, comprising: 2. The method for manufacturing a Hall element according to claim 1, wherein the step of providing the groove is to project a laser beam onto the semiconductor film.