JPH05121319A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To obtain a high IG capability without deteriorating mechanical strength by a method wherein a silicon single crystal is made to grow on a silicon single crystal substrate by epitaxial growth. CONSTITUTION:A silicon single crystal is manufactured by a high oxygen MCZ method and a substrate cut from the silicon single crystal is used. If the oxygen (Oi) concentration of the substrate is 1.0X10<10>/cm<3> or higher, the substrate is subjected to a high temperature treatment at 1100 deg.C or higher. Then it is subjected to a heat treatment at a temperature of 500-1050 deg.C. The pitches between the crystal growth stripes of the substrate is thicker than those of a CZ single crystal substrate and, after epitaxial growth, even if a device thermal treatment is performed, a thermal stress can be suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor device, and more particularly to a method for manufacturing a high-quality epitaxial substrate which is required to reduce variations in electrical characteristics of a circuit of a semiconductor silicon substrate composed of highly integrated miniaturization elements Regarding manufacturing method.

[0002]

2. Description of the Related Art Conventionally, in a semiconductor integrated circuit which is highly integrated and miniaturized, Czochralski (C
In a silicon single crystal substrate (wafer) cut out from a CZ single crystal manufactured by the Z) method, a defect-free layer (Denuded Zon) is formed on the substrate surface by performing a specific heat treatment.
e) crystal defects (Bulk Micro Defect: B
MD) are formed respectively. This BMD positively utilizes the intrinsic gettering (IG) effect of precipitating a trace amount of heavy metals and the like that enter during the manufacturing process of the semiconductor integrated circuit, thereby improving the yield.

[0003]

The IG effect is related to the concentration of oxygen ([Oi]: oxygen existing between the lattices) contained in the silicon single crystal substrate. That is, during crystal growth, excess oxygen mixed in from the crucible or the atmosphere and dissolved in silicon is precipitated inside the crystal by heat treatment,
Crystal defects are formed around the deposited portion. This formation causes strain in the crystal lattice, and heavy metal or the like is deposited by utilizing this strain field.

However, if oxygen [Oi] precipitation nuclei are formed at a high density in order to enhance the IG effect, the residual oxygen [Oi] is reduced and the mechanical strength of the silicon single crystal substrate becomes weak. For example, in the heat treatment during the manufacturing process of the semiconductor integrated circuit, dislocation defects are generated even in the electrically active region of the device circuit, and the crystal characteristics deteriorate. Therefore, the IG effect has to be controlled within a narrow range so as not to impair the device characteristics.

In addition, a ramping ratio of 0.1 ° C. is applied to a silicon single crystal substrate containing a high concentration of antimony impurities.
Although a high temperature IG effect could be obtained if the low temperature treatment step was performed at less than 1 min./min, the occupation time of the heat treatment furnace was very long, and the cost was not suitable for mass production of semiconductor devices.

An object of the present invention is to provide a single crystal silicon substrate having a high IG capability at low cost without deteriorating its mechanical strength.

[0007]

According to a first aspect of the present invention, there is provided a semiconductor device manufacturing method in which a silicon single crystal is epitaxially grown on a silicon single crystal substrate processed from a silicon single crystal manufactured by a high oxygen MCZ method. is there.

The invention described in claim 2 is the same as claim 1
The oxygen concentration in the high oxygen MCZ silicon substrate according to
In the case of 1.0 × 10 ¹⁸ / cm ³ or more, 1100 ° C
This is a method of manufacturing a semiconductor device in which epitaxial growth is performed after performing the above high-temperature treatment.

The invention described in claim 3 is the same as claim 1
In the manufacturing method described in (1), the semiconductor device is manufactured by performing high temperature treatment at 1100 ° C. or higher, further performing heat treatment at a temperature in the range of 500 to 1050 ° C., and then performing epitaxial growth.

[0010]

In the method of manufacturing a semiconductor device according to the present invention, a silicon single crystal is manufactured by the high oxygen MCZ method (CZ method in which a magnetic field controlling melt convection is set in a high-concentration oxygen atmosphere). A substrate cut out from a silicon single crystal is used. Further, the oxygen [Oi] concentration in this substrate is 1.0 × 1.
In the case of 0 ¹⁸ / cm ³ or more, high temperature treatment of 1100 ° C. or more is performed. After the high temperature treatment, heat treatment is performed in the range of 500 to 1050 ° C. Since this substrate has a denser pitch of crystal growth stripes (striation) than a CZ single crystal substrate, thermal stress is small even when device heat treatment is performed after epitaxial growth. Further, since the internal stress (strain) is small with respect to the epitaxial growth layer having no striation, no slip line (SL) is generated in the epitaxial growth layer. As a result, a substrate having high thermal mechanical strength and high IG capability can be obtained in the device manufacturing process.

[0011]

[Example] Example 1

The first embodiment will be described below. In a high-concentration oxygen atmosphere, put a silicon single crystal material in a quartz crucible, and melt this material by heating to a melting point of 14
Keep at a temperature just above 14 ° C. After immersing the seed crystal of silicon single crystal in this melt and letting it mix well,
Gently pull up while rotating the shaft and crucible. During this time, by applying a magnetic field, the oxygen concentration in the silicon single crystal is controlled while suppressing or accelerating the reaction with the crucible while the kinematic viscosity of the melt is increased. In this way, a columnar silicon single crystal having a seed crystal orientation arrangement is obtained. The high oxygen MCZ silicon single crystal thus produced is used as an epitaxial growth substrate.

Since the surface of the high oxygen MCZ silicon single crystal substrate has a smaller striation pitch and a higher density than the CZ silicon single crystal substrate, the stress field in the in-plane direction is small. A silicon single crystal thin film is epitaxially grown on this substrate. Furthermore, in the semiconductor device manufacturing process, after performing a simulation heat treatment close to the thermal history, if selective etching is performed with a Zirtor etching solution
No slip line is found in this epitaxial growth layer. That is, it can be seen that the silicon substrate has high thermal mechanical strength during the device manufacturing process.

Example 2

The second embodiment will be described below. An N-type silicon single crystal prepared by adding antimony to the high oxygen MCZ silicon single crystal of Example 1 is used as an epitaxial growth substrate.

Before the epitaxial growth, after the heat treatment at 1200 ° C., the heat treatment is performed at a temperature of 550 ° C. to 950 ° C. at a temperature rising rate of 950 ° C. higher than 0.1 ° C./min. Next, epitaxial growth is performed. Further, when the device heat treatment and selective etching are performed as in the first embodiment, the IG layer can be clarified. Ie high IG
An epitaxial substrate having an effect can be manufactured at low cost.

[0017]

As described above, according to the present invention, a semiconductor silicon substrate having a high IG capability can be manufactured at low cost without impairing the mechanical strength.

Claims (3)

[Claims] 1. A method of manufacturing a semiconductor device, which comprises epitaxially growing a silicon single crystal on a silicon single crystal substrate processed from a silicon single crystal manufactured by a high oxygen MCZ method. 2. When the oxygen concentration in the high oxygen MCZ silicon substrate according to claim 1 is 1.0 × 10 ¹⁸ / cm ³ or more, high temperature treatment of 1100 ° C. or more is performed, and then epitaxial growth is performed. A method for manufacturing a semiconductor device, which is characterized by the above. 3. The semiconductor device according to claim 1, wherein after high temperature treatment at 1100 ° C. or higher, further heat treatment is performed at a temperature in the range of 500 to 1050 ° C., and then epitaxial growth is performed. Manufacturing method.