DE1278400B - Process for producing crystalline semiconductor layers on a monocrystalline semiconductor body, in particular made of silicon - Google Patents

Description

Process for the production of crystalline semiconductor layers on a monocrystalline semiconductor body, in particular made of silicon. It is known that thin crystalline layers of semiconductor material with the help of epitaxial technology to produce a monocrystalline semiconductor body.

According to this technique, the semiconductor bodies are produced at temperatures which almost approach the melting point, pretreated in a reducing atmosphere. Then a semiconductor compound converted into the gas state by thermal conversion is produced passed over the heated semiconductor body.

It is possible to use a low-resistance base body with a high-resistance one Layer of the same or opposite conductivity or vice versa and add dopants to the semiconductor compound.

A disadvantage of this method, however, is that by the long-term, high temperature influence required for monocrystalline layer formation the life and barrier properties of the semiconductor junctions are deteriorated and that the monocrystalline layer during contacting processes in the contact area must be converted into an amorphous layer.

In addition, extensive and sometimes costly measures are required, in order to obtain a flawless monocrystalline layer of sufficient thickness and to lower the film-forming temperature as much as possible.

In the case of monocrystalline deposition, the The layer has a particularly great tendency to degenerate. Their pollution is also which is based on the materials of the device can hardly be avoided.

With the invention, the disadvantages mentioned are to be avoided and a layer formation that can be carried out with less effort, in which no post-treatment the layer is required for contacting and a more favorable yield on components is achieved.

The sensitivity of the process should be reduced and yet the physical, chemical and electronic properties of the semiconductor body and the semiconductor junction are retained.

This is achieved with a method for producing semiconductor junctions forming or easy-to-contact crystalline layers of semiconductor material on a monocrystalline semiconductor body, in particular made of silicon, by thermal or electrothermal decomposition or reduction of volatile semiconductor compounds after a thermal reducing pretreatment of the semiconductor body, if according to the invention the thermal pretreatment is carried out at a temperature at which would form a monocrystalline layer, or if the thermal pretreatment at this temperature by admixing the semiconductor compounds to the reducing Gas atmosphere is made together with a monocrystalline layer formation and if for the actual deposition process the temperature of the semiconductor body below the monocrystalline film formation temperature to a temperature at the polycrystalline layer formation occurs is lowered.

It is desirable that the monocrystalline layer only up to a thickness of 1 im growing up. The level of the monocrystalline film formation temperature depends on the type of procedure, especially on the semiconductor compound used addicted. If not already known, this is to be determined empirically.

For growing such layers on Si semiconductor base bodies two methods have been successfully found, which are explained for example.

The basis for the examples is to grow a low-resistance Si layer on a high-resistance Si base body of the opposite conductivity type. Example 1 The Si base body is thermally etched at 1200 ° C. for 10 to 15 minutes under hydrogen gas, then the temperature is lowered to 900 to 1000 ° C. and the Si deposition process from the compound SiC14 is initiated. Depending on the intended use, the deposition time is 1 to 30 minutes, and a pure polycrystalline layer is created. Example 2 The Si base body is heated at 1200 ° C. under hydrogen gas for 10 to 15 minutes and then at the same temperature a deposition of the compound SiC14 is initiated to form a monocrystalline, epitaxial layer -Base body lowered to 900 to 1000 ° C and polycrystalline layer formation continued up to the desired mixed layer thickness. The monocrystalline layer is preferably limited to a thickness of 1 μm.

Claims (2)

Claims: 1. Method for producing semiconductor junctions forming or easy-to-contact crystalline layers of semiconductor material on a monocrystalline semiconductor body, in particular made of silicon, by thermal or electrothermal decomposition or reduction of volatile semiconductor compounds after a thermal reducing pretreatment of the semiconductor body, thereby characterized in that the thermal pretreatment is carried out at one temperature in which a monocrystalline layer would form, or that the thermal Pretreatment at this temperature by adding the semiconductor compounds to the reducing gas atmosphere together with a monocrystalline layer formation is made and that the temperature for the actual deposition process of the semiconductor body below the monocrystalline layer formation temperature up to a temperature at which polycrystalline film formation occurs is lowered. 2. The method according to claim 1, characterized in that the temperature is lowered at a maximum thickness of 1 gm of the monocrystalline layer. Considered publications: German Auslegeschriften Nos. 1029 941, 1048638.