JP3670513B2 - Method for producing silicon single crystal - Google Patents

Description

【００２４】
本発明のシリコン単結晶の製造方法に用いられるドーパントを用いて引き上げた実施例では、気泡の発生個数が少なく、ＤＦ率は１００％となった。
【００２５】
各実施例の抵抗値はほぼ同一の値を示し、抵抗値を容易、かつ正確に制御できることがわかった。
【００２６】
【発明の効果】
本発明に係わるシリコン単結晶の製造方法によれば、砒素ドーパントの供給による気泡の発生を抑制して、転位により結晶成長が阻害されるのを防止し、シリコン単結晶製造時のＤＦ率を高位に維持できる。
【００２７】
また、被膜を積極的にドーパント本体に被覆するので、短時間に被膜の形成ができ、ドーパントの前処理に時間を要せず、ドーパントの多くの在庫を持つ必要もない。
【図面の簡単な説明】
【図１】 本発明に係わるシリコン単結晶の製造方法に用いられる砒素ドーパントの説明図。
【図２】 本発明に係わるシリコン単結晶の製造方法に用いられる製造装置の説明図。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a divorced single crystal, a method for manufacturing a silicon single crystal, in particular the addition of dopant subjected to coating arsenic.
[0002]
[Prior art]
A substrate of a semiconductor element is manufactured mainly from a high-purity silicon single crystal, and the Czochralski method (CZ method) is generally used as a method for manufacturing this silicon single crystal. In the CZ method, a polycrystalline silicon raw material is stored in a quartz glass crucible, heated by a heater from around the crucible containing the silicon raw material, the silicon raw material is melted, the seed crystal is immersed, and the seed crystal is rotated. The silicon single crystal is manufactured by pulling it up.
[0003]
In order to change the resistivity of the silicon single crystal according to the purpose of use, the silicon single crystal to be manufactured contains a small amount of boron, phosphorus, antimony (Sb), arsenic (As), etc. during the silicon single crystal manufacturing process. A dopant is added to the silicon melt.
[0004]
In general, boron and phosphorus, which have relatively high melting points, are filled in a quartz glass crucible together with the raw material polycrystalline silicon, heated, melted, and dissolved in the melt.
[0005]
On the other hand, As and Sb have a large evaporation coefficient during melting and are difficult to precisely control. However, since they have a high solid solubility at the melting point, they are often used in the case of attachment at a high concentration. In particular, As has a maximum solid solubility and is extremely low. A resistivity crystal is obtained.
[0006]
As and Sb, which have a relatively low melting point, are dropped directly into the silicon melt and added to the melt.
[0007]
However, when As is dropped and added to the silicon melt, it reacts with oxygen in the melt to generate a gas mainly composed of AsO. This gas becomes bubbles having a diameter of several millimeters or less and is released from the melt surface to the outside of the melt. When this gas containing AsO as a main component adheres to the crystal growth interface, dislocation occurs from the adhering portion, and crystal growth is often hindered by the dislocation, and the DF ratio (silicon single crystal The ratio of the dislocation-free length to the standard straight body length) was reduced.
[0008]
As a measure for preventing a decrease in the DF ratio during the production of a silicon single crystal, Japanese Patent No. 2766189 discloses that the arsenic dopant includes metal arsenic, or metal arsenic and a silicon compound. A dopant that is left for a week to form an oxide film on the surface of the dopant and a method for producing a silicon single crystal using the dopant are described.
[0009]
However, in the described method for forming a film of a dopant, since oxygen in the atmosphere and arsenic on the surface of the dopant are naturally oxidized to form an oxide film, it takes time to form the film, and a large amount of dopant raw material is in stock. In addition, it was difficult to form a uniform oxide film.
[0010]
[Problems to be solved by the invention]
Therefore, by suppressing the reaction between O and As in silicon melt, AsO can suppress the generation of bubbles mainly composed of, and in a short time in film formation can be easily, coating uniform arsenic dopant bets method for manufacturing a silicon single crystal using has been demanded.
[0011]
The present invention has been made in consideration of the above-described circumstances, and suppresses the reaction between O and As in a silicon melt, thereby suppressing the generation of bubbles mainly composed of AsO and forming a film in a short time. and an object thereof is easily possible, the coating provides a method for manufacturing a silicon single crystal using a uniform arsenic dopant bets.
[0012]
[Means for Solving the Problems]
The invention of claim 1 of the present invention made to achieve the above object is a method for producing a silicon single crystal in which a silicon single crystal is grown from a seed crystal by bringing the seed crystal into contact with a silicon raw material melt contained in a container. Supplying a silicon raw material to the container and melting it, adding a dopant to the silicon raw material melt and dissolving it in the melt, bringing the seed crystal into contact with the silicon raw material melt, And using an arsenic dopant in which a dopant body made of arsenic is coated with arsenic oxynitride as the dopant .
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a manufacturing method of Resid silicon single crystal involved in the present invention with reference to the drawings.
[0014]
FIG. 1 shows an arsenic dopant 1 used in a method for producing a silicon single crystal according to the present invention. The arsenic dopant 1 has a mean particle diameter of 1 to 2 mm and is made of arsenic, and the surface of the dopant body 2 is coated. The coated film 3 is formed. This coating 3 is arsenic oxynitride selected from arsenic compounds. The coating 3 is formed by blowing a raw material such as oxygen or silicon into the granular arsenic dopant body 2 by a conventional coating forming process to form a coating 3 having a thickness of several μm.
[0015]
A method for manufacturing the Resid silicon single crystal involved in the present invention the addition of the arsenic dopants.
[0016]
Production of a silicon single crystal by the CZ method using a single crystal production apparatus 11 as shown in FIG. 2 is performed by filling a quartz crucible 13 installed in the apparatus main body 12 with polycrystalline silicon as a small lump shape raw material, After the polycrystalline silicon is completely heated and melted by the heater 14 provided on the outer periphery of the crucible 13, the seed crystal (seed crystal) S attached to the seed chuck 15 is immersed in the silicon melt M, so that the seed crystal S and the quartz crucible are immersed. 13 is rotated in the reverse direction to pull up the seed crystal S to grow a silicon single crystal Ig.
[0017]
During the single crystal pulling step, the arsenic dopant 1 is supplied in a predetermined amount from the dopant supply pipe into the molten silicon melt M.
[0018]
As shown in FIG. 1, the surface of the arsenic dopant 1 supplied to the high-temperature silicon melt is covered with a coating 3, and the reaction between O and As in the silicon melt M is suppressed, and AsO is reduced. Since the generation of bubbles as a main component is suppressed, the generation of bubbles in the vicinity of the solid-liquid interface of the silicon ingot Ig where arsenic is easily condensed is suppressed.
[0019]
Therefore, dislocation due to bubbles does not occur in the vicinity of the solid-liquid interface, and crystal growth is not hindered by the dislocation. For this reason, the DF rate at the time of manufacturing a silicon single crystal is not reduced.
[0020]
【Example】
An example in which a silicon single crystal is pulled under the following pulling conditions using the method for manufacturing a silicon single crystal according to the present invention will be described.
[0021]
(1) Pulling conditions Crystal diameter 130mm, raw material weight 35kg, dopant weight 200g
[0022]
(2) Coating material a) Arsenic oxynitride ( Example)
b) No coating (conventional example)
[0023]
result
[Table 1]

[0024]
In the example pulled up using the dopant used in the method for producing a silicon single crystal of the present invention, the number of bubbles generated was small and the DF ratio was 100%.
[0025]
The resistance values of the respective examples showed almost the same values, and it was found that the resistance values can be controlled easily and accurately.
[0026]
【The invention's effect】
According to the manufacturing method of Resid silicon single crystal involved in the present invention, by suppressing the generation of bubbles due to the supply of arsenic dopant, dislocations prevents the crystal growth is inhibited, DF during silicon single crystal manufacturing The rate can be kept high.
[0027]
In addition, since the coating is positively coated on the dopant body, the coating can be formed in a short time, and the pretreatment of the dopant does not require time, and it is not necessary to have a large inventory of dopant .
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of an arsenic dopant used in a method for producing a silicon single crystal according to the present invention.
FIG. 2 is an explanatory view of a manufacturing apparatus used in the method for manufacturing a silicon single crystal according to the present invention.

Claims (1)

In a silicon single crystal manufacturing method of growing a silicon single crystal from a seed crystal by bringing the seed crystal into contact with a silicon raw material melt contained in the container, a step of supplying and melting the silicon raw material into the container, and the silicon raw material A dopant body made of arsenic as the dopant, the method comprising adding a dopant to the melt and dissolving it in the melt; and bringing the seed crystal into contact with the silicon raw material melt and pulling up the silicon single crystal A method for producing a silicon single crystal, characterized by using an arsenic dopant coated with arsenic oxynitride .

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