JPH0661261A - Manufacture of compound semiconductor device - Google Patents

Abstract

PURPOSE:To provide a manufacturing method of a compound semiconductor device which makes the formation of a thin film-like fine doped region possible in an operational layer without generating defect in a semiconductor crystal in a compound semiconductor whose main constituent element is a III-V compound semiconductor. CONSTITUTION:In a ultra-vacuum device, an extremely thin doped region is formed in an electron beam directing region through a first process for depositing a similar or dissimilar compound semiconductor crystal 2 on a compound semiconductor substrate 1, a second process for forming a thin film-like doped layer 5 in the electron beam directing region by directing an electron beam 3 to a compound semiconductor crystal in gaseous atmosphere 4 which contains silicon compound or carbon compound and a third process for further depositing a similar or dissimilar compound semiconductor crystal 6 on the compound semiconductor crystal 2 whereto an electron beam is directed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for adding an impurity in the manufacture of a compound semiconductor device containing a Group 3 or Group 5 compound semiconductor as a main constituent element, and particularly uses an extremely thin layer impurity-doped region called delta doping. The present invention relates to a method for manufacturing a compound semiconductor device used for manufacturing all semiconductor devices.

[0002]

2. Description of the Related Art In the manufacture of semiconductor devices, as a method of adding impurities, a method of simultaneously performing formation of a host crystal, a method of using diffusion of an impurity element from a surface to a host material, and a method of ionizing the impurity element to provide a host crystal The method of driving in is widely used. Also, a method of depositing an impurity layer on the crystal surface and then injecting the impurity into the crystal by irradiating a very high energy electron beam is a physical review, 1984, Volume B30, No. 6, page 3384, (Physi
cal Review Vol.B30 p.3384). In particular, in the method performed simultaneously with the formation of the host crystal, it is known that the impurity addition in which the impurity added region is an extremely thin thin film is called delta doping or the like and is effective for manufacturing a transistor having high mobility. .

[0003]

Among the above methods, for example, in the method which is carried out simultaneously with the formation of the host crystal, photolithography or the like and etching are performed to partially remove the impurity-added layer formed in the entire crystal plane. Will be required. Even in the method using the diffusion of the impurity element, photolithography or the like is still necessary to form the impurity-added region only in the specific region. However, the fine pattern formed by photolithography or the like has a limit of about 100 nm, which is a major obstacle in manufacturing a semiconductor device having a finer impurity-doped region.

Further, in the method of ionizing an impurity element and implanting it in a host crystal, a fine impurity-doped region can be formed by focusing ions, but ion irradiation causes defects in the semiconductor crystal, and There is a drawback that it is difficult to add thin film impurities. Furthermore, the method of implanting impurities by an electron beam has the same drawbacks.

The present invention is intended to solve the above problems, and in a compound semiconductor having a Group 3 or Group 5 compound semiconductor as a main constituent element, a thin film is formed in the operating layer without generating defects in the semiconductor crystal. An object of the present invention is to provide a method for manufacturing a compound semiconductor device capable of forming a fine impurity-doped region in a shape.

[0006]

In order to solve the above-mentioned problems, the method of manufacturing a semiconductor device according to the present invention deposits the same kind or different kinds of compound semiconductor crystals on a compound semiconductor substrate in an ultrahigh vacuum apparatus. And a second step in which a compound semiconductor crystal is irradiated with an electron beam in a gas atmosphere containing a silicon compound or a carbon compound to form a thin-film impurity-added layer in the electron beam irradiation region. A compound semiconductor in which an extremely thin impurity-doped region is formed in an electron beam irradiation region is manufactured by a third step of further depositing the same or different compound semiconductor crystal on the electron beam-irradiated compound semiconductor crystal. It is what

[0007]

When the crystal deposition, sample transport, etc. are all performed in an ultra-high vacuum apparatus, the impurity atoms present on the crystal surface can be kept at an extremely low concentration, for example, Kakuya et al.
Proceedings of the Joint Lectures on Applied Physics No.1, 328, 31
Shown in aZA4. Therefore, when the crystal deposition is once interrupted and a process such as impurity addition is performed, the impurity incorporation other than the arbitrary impurity addition can be suppressed to a sufficiently low concentration in the ultra-high vacuum apparatus. .

On the other hand, a silicon compound or a carbon compound is decomposed by electron beam irradiation to attach silicon or carbon atoms to the semiconductor surface. In Group 3 and Group 5 compound semiconductors, when silicon of one molecular layer or less is incorporated into the crystal surface, it becomes an N-type impurity, and when carbon of one molecular layer or less is incorporated into the crystal, it becomes a P-type impurity. . Therefore, when performing crystal deposition, electron beam irradiation, and crystal re-deposition in an ultra-high vacuum device,
An N-type or P-type impurity element is added only to the electron beam irradiation region.

It is a well known fact that the electron beam can be easily focused and an electron beam having a beam diameter of 1 nm or less can be obtained. Therefore, according to the method for manufacturing a semiconductor device of the present invention,
It is possible to manufacture a semiconductor device having an extremely fine N-type or P-type impurity-added region. In addition, the method of adding impurities according to the present invention is, in principle, a thin film-like impurity addition, and is suitable for manufacturing a high mobility transistor or the like.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a method 1 for manufacturing a compound semiconductor device of the present invention.
FIG. 3 is a diagram showing a procedure of a method for forming an operation layer region for explaining an embodiment, wherein 1 is a compound semiconductor substrate, 2 and 6 are compound semiconductor crystals, 3 is silane or methane, etc., 4 is an electron beam, and 5 is impurity addition. A region (silicon or carbon), 7 indicates an electron beam irradiation region.

First, as shown in FIG. 1A, as a first step, a compound semiconductor crystal 2 of the same kind or different kind, for example, gallium arsenide or aluminum gallium arsenide is placed on a compound semiconductor substrate 1, for example, gallium arsenide. It is formed by a molecular beam epitaxial growth method or the like.

Next, as shown in FIG. 1B, as a second step, an impurity-doped region 5 on the surface of the compound semiconductor crystal 2 is used.
Silane (SiH ₄ ) 4 is used to form an N-type conductive layer on the
The electron beam 3 is selectively irradiated in a gas atmosphere such as, and when the P-type conductive layer is formed, the electron beam 3 is selectively irradiated in a gas atmosphere such as methane (CH ₄ ) 4.

Finally, as shown in FIG. 1 (c), in the third step, aluminum is again used as the compound semiconductor crystal 6 of the same kind or different kind on the compound semiconductor crystal 2 irradiated with the electron beam by the molecular beam epitaxial growth method or the like.・ Form gallium arsenide.

In order to prevent unintended adhesion of impurities, all of these three steps are carried out in an ultra-high vacuum apparatus having an ultimate vacuum of 1 × 10 ^-8 Torr or less when the source gas supply is stopped. In this method, since no defect is generated in the crystal, the impurity-added region 5 is activated without using a step such as annealing and becomes an operation region.

FIG. 2 is a schematic view of a field effect transistor manufactured by the method for manufacturing a semiconductor device according to the present invention.
Is a drain electrode, 9 is a gate electrode, and 10 is a source electrode. Such a field effect transistor is shown in FIG.
It can be manufactured by forming each of the source electrode 10, the gate electrode 9, and the drain electrode 8 on the compound semiconductor crystal shown in 1 above by using ordinary photolithography or the like.

According to the compound semiconductor crystal produced by the method of the present invention, since the crystal surface is flat, it is possible to easily form a fine electrode structure.

FIG. 3 is a sectional view showing the outline of a compound semiconductor laser having a periodic modulation structure of electrostatic potential, which is manufactured by using the method for manufacturing a semiconductor device of the present invention. By forming a heterogeneous compound semiconductor crystal 2 having an in-plane modulation periodic structure composed of an extremely thin impurity-doped region 5 as an operating layer on the compound semiconductor substrate 1 using the method of the present invention, the compound semiconductor crystal 6 is sandwiched between the compound semiconductor crystals 6. A compound semiconductor laser having a sharp wavelength selectivity can be manufactured by using a Bragg reflector for a periodic distribution of gain or carriers.

[0018]

As is apparent from the above description, according to the present invention, since a thin impurity-doped layer is formed only in a region irradiated with an electron beam, a fine operating layer region or a minute period is formed. A compound semiconductor device having an in-plane potential distribution can be easily formed. Further, at this time, since irradiation of the electron beam in the ultra-high vacuum apparatus does not generate defects in the host crystal, steps such as annealing for recovering the defects are not required, and the yield of semiconductor device manufacturing is improved. Is improved.

[Brief description of drawings]

FIG. 1 is a diagram showing a procedure of an operating layer region forming method for explaining one example of a method for manufacturing a compound semiconductor device according to the present invention.

FIG. 2 is a schematic view of a field effect transistor manufactured by using the method for manufacturing a semiconductor device of the present invention.

FIG. 3 is a schematic view of a semiconductor laser provided with a periodic modulation structure of electrostatic potential, which is manufactured by using the method for manufacturing a semiconductor device of the present invention.

[Explanation of symbols]

1 ... Compound semiconductor substrate, 2, 6 ... Compound semiconductor crystal, 3
... Silane, methane, etc., 4 ... Electron beam, 5 ... Impurity added region (silicon or carbon), 7 ... Electron beam irradiated region, 8 ... Drain electrode, 9 ... Gate electrode, 10 ... Source electrode.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Internal reference number FI Technical display location H01S 3/18 // H01L 21/203 M 8422-4M (71) Applicant 592171809 Takashi Yoshida Suginami, Tokyo 3-31-14 Ogikubo Ward Asahi Kasei Ogikubo Dormitory (72) Inventor Hiroyuki Sakaki 174-260 Oba-cho, Midori-ku, Yokohama-shi, Kanagawa Prefecture (72) Yutaka Kakuya 4-50-27 Kugayama, Suginami-ku, Tokyo Conform Kugayama 202 (72) Inventor Hiroshi Noge 4-34-17 Kugayama, Suginami-ku, Tokyo 2nd floor, Ando (72) Inventor Shinji Mitsuya 1000 Kawanarijima, Fuji-shi, Shizuoka Asahi Kasei Godori (72) Inventor Takashi Yoshida Ogikubo, Suginami-ku, Tokyo 3-31-14 Asahi Kasei Ogikubo Dormitory

Claims (2)

[Claims] 1. A first step of depositing the same kind or different kinds of compound semiconductor crystals on a compound semiconductor substrate in an ultra-high vacuum apparatus, and electrons in the compound semiconductor crystals in a gas atmosphere containing a silicon compound or a carbon compound. A second step of forming a thin film impurity-doped layer in the electron beam irradiation region by irradiating the electron beam, and a third step of further depositing the same or different compound semiconductor crystal on the electron beam irradiated compound semiconductor crystal A method of manufacturing a compound semiconductor device, characterized in that a compound semiconductor in which an extremely thin impurity-added region is formed in the electron beam irradiation region is manufactured by the step of. 2. The method of manufacturing a compound semiconductor device according to claim 1, wherein the second step of irradiating with an electron beam is performed in a gas atmosphere containing a silicon compound when N-type impurities are added, and the second step is performed. A method of manufacturing a compound semiconductor device, characterized in that the impurity is added in a gas atmosphere containing a carbon compound.