JPH10256157A - Method of growing n-type gaas semiconductor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a semiconductor device including a p- and n-type high-quality modulation doped structures on a GaAs substrate having a specified orientation plane by growing an n-type GaAs layer with a dopant of Sn of the substrate by the molecular beam epitaxy. SOLUTION: To grow an n-type GaAs layer on a GaAs substrate having a plane (311) A by the molecular beam epitaxy, at least Sn is used as a dopant to obtain a semiconductor structure contg. n- and p-type dopants on a GaAs semi-insulating substrate 1 having a plane (311) A. This substrate contains a Si-doped AlGaAs/GaAs modulation doped structure and Sn-doped AlGaAs/ GaAs modulation doped structure. Thus, at the interfaces on both sides of a central thicken undoped GaAs layer 4 a two-dimensional electron gas 2DEG 6 and two-dimensional hole gas 2DHG 7 are formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to GaAs (311).
The present invention relates to a method for growing a high-quality n-type semiconductor layer on an A substrate.

[0002]

2. Description of the Related Art Conventionally, a molecular beam epitaxy (MBE) method has been generally used as a method for manufacturing a high mobility (mobility) transistor based on GaAs and InP-based compound semiconductors. (100) -oriented substrate, n-type dopant such as Si, p-type dopant B
e and the like are used. However, in the p-type, in addition to the large effective mass of holes, there are problems of diffusion of Be into the channel, purity of the Be source itself, and low mobility. On the other hand, GaAs (3
11) When the A substrate is used, a p-type AlGaAs / GaAs modulation doped structure using Si as an acceptor is produced by utilizing the fact that Si is taken in as an acceptor.
An ultra-high mobility of μ> 100 m ² / Vs has been realized [M. Henini, PJ Rodgers, PACrump, BLGallaghe
r, and G.Hill, J.Cryst.Growth, Vol.150, (1995) p.451-
454.]. However, when a GaAs (311) A substrate is used, there is a problem that there is no appropriate n-type dopant. S
Since i is bipolar, it becomes n-type by growing at low temperature and high As pressure [N. Sakamoto, K. Hirakawa, and T. Ikom
a, Appl.Phys.Lett., Vol.67, No.10. (1995) p.1444-144
6.] Under such conditions, it was difficult to obtain a high-quality n-type semiconductor layer with good controllability.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a Ga
Taking advantage of the characteristic that Si, which is a feature of the As (311) A substrate, acts as an acceptor to form a high-quality p-type semiconductor layer, p-type semiconductor layers are further formed on the GaAs (311) A substrate surface.
It is an object of the present invention to provide a method for growing n-type GaAs by an n-type doping method which enables formation of a semiconductor device including a high-quality modulation doping structure of both the n-type and the n-type.

[0004]

Means for Solving the Problems In order to achieve the object of the present invention, the present invention is configured as described in the claims. That is, in the method of growing an n-type GaAs semiconductor on a GaAs substrate having a (311) A plane by a molecular beam epitaxy method, the growth of the n-type GaAs semiconductor using at least Sn as a dopant is as described in claim 1. Method. The present invention provides a GaAs (311) A
In growing an n-type GaAs layer on a substrate by a molecular beam epitaxy method, using at least Sn as a dopant has an effect of easily forming a high-quality n-type doping layer.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION

<Embodiment 1> Table 1 shows this embodiment. In the present embodiment, a Sn-doped GaAs layer having a thickness of 1 μm is formed at 520 ° C. by GaAs (3
11) This shows the case where the substrate is grown on the A substrate. Both the carrier concentration n (1 / cm ³ ) and the mobility μ (cm ² / Vs) of the obtained n-type epitaxial layer are usually used (100)
It can be seen that Sn behaves as a stable donor on the GaAs (311) A substrate, comparable to the Si-doped n-type epitaxial layer on the substrate.

[0006]

[Table 1]

<Embodiment 2> In this embodiment,
(311) A n-type, on the GaAs semi-insulating substrate 1
A semiconductor structure including both p-type dopings is shown in FIG.
This structure includes a Si-doped AlGaAs / GaAs modulation-doped structure and a Sn-doped AlGaAs / GaAs.
A modulation doping structure is included. Therefore, a two-dimensional electron gas (2DEG) 6 and a two-dimensional hole gas (2DHG) 7 are formed at the interface on both sides of the thick non-doped GaAs layer indicated by reference numeral 4 in the center. Measured mobility μ
Is 10 ⁶ cm ^{2 /} Vs (1.6 for (2DEG) 6).
K), 5 × 10 ⁵ cm ² / Vs for (2DHG) 7
(1.6K), indicating that 2DEG and 2DHG having high mobility are formed on the same (311) A GaAs substrate 1. In the present embodiment, the modulation doping structure is described in order to show the formation of high quality n-type and p-type layers. A pn junction on the GaAs (311) A plane is also possible. In addition, if the thickness of the non-doped GaAs layer 4 is controlled in the structure of FIG.

[0008]

According to the present invention, GaAs (311) A
It is possible to form both p-type and n-type high-quality doped structures on a substrate, which makes it possible to form a higher quality than the conventional n-type and p-type structures obtained by Si doping and Be doping on the (100) plane. A high-quality semiconductor device including p-type and n-type can be realized.

[Brief description of the drawings]

FIG. 1 illustrates (311) A exemplified in Embodiment 2 of the present invention.
FIG. 3 is a schematic diagram showing an example in which both n-type and p-type doping structures are formed on a GaAs semi-insulating substrate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... (311) A GaAs semi-insulating substrate and buffer layer 2 ... Non-doped AlGaAs layer 3 ... Si-doped AlGaAs layer 4 ... Non-doped GaAs layer 5 ... Sn-doped AlGaAs layer 6 ... 2D electron gas (2DEG) 7 ... 2D Hole gas (2DHG)

Claims (1)

[Claims] 1. A method for growing an n-type GaAs semiconductor on a GaAs substrate having an A-plane by molecular beam epitaxy, wherein at least Sn is used as a dopant. .