JPS6249995B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel method for manufacturing magnetoelectric transducers based on dry etching using light irradiation through a mask. The conventional manufacturing method for magnetoelectric transducers involves etching a thin film of a magnetically sensitive semiconductor such as a compound semiconductor, mainly composed of group elements, formed on a substrate with a strong acid solution to create a desired pattern; The device was manufactured by forming a magnetically sensitive portion and electrodes on the pattern. The method of patterning a semiconductor thin film and manufacturing a magnetoelectric transducer by etching with such a solution involves a complicated process, and it is difficult to manage the solution and process each step.
There were problems such as the need for processing. For this reason, attempts have been made to fabricate magnetoelectric transducers by patterned vapor deposition of the above-mentioned compound semiconductors, etc., to form device patterns, but it is extremely difficult to vaporize fine patterns of thin films, and it is difficult to mass-produce the devices. It was not even possible to obtain a magnetoelectric transducer with such characteristics. Now, dry patterning is the best way to manufacture magnetoelectric transducers with good characteristics in a simple process that does not require waste liquid treatment, and the establishment of this manufacturing technology is strongly desired in this field. It is something. In view of this situation, the present inventors have diligently researched dry patterning technology, and as a result, have found that:
When group-group compound semiconductors or single-crystal or polycrystalline thin films of Si or Ge are irradiated with light energy above a certain threshold, they easily become fine particles, are dispersed, and removed, resulting in particles of 5 particles/mm or more. They have discovered that a pattern with high resolution can be formed, and have completed the present invention. That is, the present invention comprises a step of forming a magnetically sensitive semiconductor thin film consisting of a compound semiconductor mainly composed of group elements and group elements and Si and Ge on a substrate, and dry etching the thin film by irradiating light through a mask. A method for manufacturing a magnetoelectric transducer, comprising the steps of patterning and forming a magnetically sensitive part of the magnetoelectric transducer in an unetched portion of the thin film. The method for manufacturing a magnetoelectric transducer of the present invention generally includes:
It can be applied to all magnetoelectric conversion elements that use single-crystal or polycrystalline magnetically sensitive semiconductor thin films. The present invention is preferably applied to Hall elements, magnetoresistive elements, and three-terminal magnetoresistive elements. The magnetically sensitive semiconductor thin film used in the magnetoelectric transducer to which the present invention is applied is made of a compound semiconductor consisting of a combination of group and group elements, or a single crystal or polycrystal of Si or Ge. It can be produced using methods such as growth method, liquid phase growth method, vacuum evaporation, sputtering, and ion plating. The thickness of the thin film is determined depending on the device to be manufactured and its characteristics, but is preferably 0.2 to 5 μm.
It is. The hole mobility of the semiconductor majority carrier is preferably large, and it is particularly preferable that the semiconductor has an electron mobility of 5000 cm ² /V.Sec or more at room temperature. Preferred compound semiconductors consisting of group and group elements include InSb, InAs, GaAs, InP, and
There are single crystals and polycrystals such as InSbSn series, InSbGa series, InSb-NiSb series, etc. In the present invention, there is no restriction on the substrate of the magnetoelectric transducer. Generally, any material used in magnetoelectric transducers can be used, but preferred ones include ferromagnetic substrates, resin substrates, glass, ceramic, and mica substrates. If necessary, these may have a surface treatment. As a method for forming the semiconductor thin film on a substrate, a general method for forming a thin film on a substrate is usually used. Preferred methods include vacuum evaporation of a semiconductor onto a substrate, sputtering, ion plating, thin film formation by vapor phase growth, and thin film formation by liquid phase growth. In some cases, it may be glued onto the substrate. Furthermore, it is also preferable to bond a thinly polished single crystal thin film onto the substrate. In order to form a pattern by dry etching using light irradiation through a mask according to the present invention, etching is performed by irradiating a semiconductor thin film with strong light energy exceeding a certain threshold value in a pattern through a mask. This is to create a pattern that forms the magnetic sensing part and electrode of the magnetoelectric transducer. Below this threshold energy, good dry etching is not possible and patterning of semiconductor thin films is not possible. The threshold energy differs depending on the type, thickness, crystallinity, etc. of the semiconductor thin film. The light energy used in the dry etching of the present invention includes strong flash light, laser light, and the like, and any of them can be preferably used. In the present invention, a magnetically sensitive semiconductor thin film formed on a substrate is irradiated with the light energy in a pattern through a mask and dry etched to form a pattern having the form necessary for a desired magnetically sensitive element. get it. Masks used when irradiating light energy in a pattern through a mask include commonly used chrome masks, metal hard masks, resist masks, etc., but these may vary depending on the light energy used. You can choose something. The magnetoelectric transducer has a magnetically sensitive part having a necessary form depending on the type and characteristics, and only the magnetically sensitive part is sensitive to magnetism. The shape of the magnetically sensitive part is generally rectangular, square, cross-shaped, disc-shaped, semicircular, etc., as well as modified or curved shapes. , electrodes, or short bar electrodes. Usually, the shape and dimensions are determined depending on the type of magnetoelectric transducer and its characteristics, and a suitable one is used. FIG. 1 shows a pattern of a magnetically sensitive part of a Hall element as an example. 1 is a substrate, 2 is a magnetically sensitive semiconductor thin film pattern patterned by dry etching using light irradiation,
It is shown with a thick line. 3 is a magnetic sensing part, and 4 is an electrode. FIG. 2 shows an example of a magnetoresistive element without a shot bar, in which 1 is a substrate, 2 is a magnetically sensitive semiconductor thin film pattern patterned by dry etching using light irradiation, and the part indicated by a thick line is like this. 3
is a magnetic sensing part, and 4 is an electrode. The magnetically sensitive part forming step of the present invention consists of forming a magnetically sensitive part in a desired shape by covering a part of the magnetically sensitive thin film pattern with another material or changing it to another material. In the present invention, the magnetically sensitive portion can be formed by applying a commonly used method on an unetched portion of a magnetically sensitive semiconductor thin film that has been patterned by dry etching using light irradiation through a mask. However, preferably, on the unetched portion of the thin film,
A method is used to form a magnetically sensitive part of a magnetoelectric transducer by forming a thin layer of a conductive material. The thin layer of conductive material has a pattern necessary for the type and characteristics of the magnetoelectric conversion element, and is formed by dry plating such as vapor deposition, sputtering, ion plating, electroless plating, electrolytic plating, etc. It is formed using a thin metal film or a thin layer of conductive resin paste. The formation of the magnetically sensitive portion may be performed in combination with the formation of the electrodes of the magnetoelectric transducer, or may be performed separately, and both are equally useful. The manufacturing method of the present invention can be applied to all magnetoelectric conversion elements made of semiconductor thin films.
However, among these, particularly preferred are a Hall element, a magnetoresistive element, and a three-terminal magnetoresistive element. The method of manufacturing a magnetoelectric transducer based on dry etching using light irradiation through a mask according to the present invention greatly simplifies the process compared to the conventional manufacturing method that uses wet etching. There is no need to treat etching waste liquid. Furthermore, since it does not cause deterioration of the characteristics of the semiconductor thin film, devices with good characteristics can be manufactured. In addition, it has extremely excellent features, such as being suitable for mass production of devices and capable of wafer processing, making it possible to reduce the cost of devices. Next, examples of the magnetoelectric transducer of the present invention will be described. Here, we took the Hall element prototype as an example, but
Of course, it can also be applied to other magnetoelectric conversion elements. Example 1 A polycrystalline semiconductor thin film of InSb having a thickness of 0.8 μm was deposited on mica at a substrate temperature of 410° C. Next, at room temperature,
After depositing 0.2μ thick SiO on the surface of InSb,
This thin film was adhered to a 0.5 mm thick ferrite substrate using Asahi Kasei epoxy resin, the epoxy was cured by heating, and the mica was peeled off. In this way, a magnetically sensitive semiconductor thin film of InSb was formed on the ferrite substrate. Next, as shown in FIG. 1, in order to form a magnetically sensitive semiconductor thin film pattern in the shape of a Hall element on the substrate 1, pattern exposure was performed through a chrome mask using flash light from a xenon lamp as a light source. In this way, a magnetically sensitive semiconductor thin film pattern 2 as shown in FIG. 1 was formed. Next, the thickness is 2μ
A pattern of Ag was vapor-deposited only on the shaded area in FIG. 1 to form electrode 4, and the remaining area was used to form a desired magnetically sensitive part 3 having a length of 0.8 mm and a width of 0.4 mm. At this time, 100 Hall elements were simultaneously manufactured on one wafer (ferrite substrate). The characteristics of the Hall element prototyped in this way are shown in Table 1.

[Table] Example 2 On a ferrite substrate with SiO ₂ sputtered to a thickness of 0.3μ on the surface, InSb was deposited to a thickness of 1 at a substrate temperature of 400℃.
A magnetically sensitive semiconductor thin film was formed by micro-evaporation. Next, in order to form a magnetically sensitive semiconductor thin film pattern in the shape of a Hall element as shown in FIG. 1, pattern exposure was performed through a chrome mask using flash light from a xenon lamp as a light source. In this way, a magnetically sensitive semiconductor thin film pattern 2 as shown in FIG. 1 was formed on the substrate 1. Next, in order to form the magnetically sensitive part 3 of the Hall element having a length of 0.8 mm and a width of 0.4 mm, a pattern of Ag having a thickness of 2 μm was deposited except for this part. In this way, 100 Hall elements were formed on the ferrite substrate. The characteristics of the Hall element thus prototyped were as follows: Product sensitivity (average value): 12 mV/mA.
KG, unbalanced voltage ±5mV when input control current is 5mA
There were 94 items below.

[Brief explanation of the drawing]

FIG. 1 shows an example of a Hall element formed on a substrate, and FIG. 2 shows an example of a magnetoresistive element without a shot bar.

Claims (1)

[Claims] 1. A step of forming a magnetically sensitive semiconductor thin film made of a compound semiconductor mainly composed of a combination of Group and Group elements or Si or Ge on a substrate, and dry-forming the thin film by irradiating the thin film with light through a mask. 1. A method for manufacturing a magnetoelectric transducer, comprising the steps of etching and patterning, and forming a magnetic sensing part of the magnetoelectric transducer in an unetched portion of the thin film. 2. The method of manufacturing a magnetoelectric transducer according to claim 1, which comprises the step of forming a magnetically sensitive part of the magnetoelectric transducer by forming a thin layer of a conductive material on the unetched portion of the thin film. 3 The magnetoelectric conversion element is a Hall element, a magnetoresistive element,
2. The method of manufacturing a magnetoelectric transducer according to claim 1, wherein the magnetoresistive element is a three-terminal magnetoresistive element.