JPH023291B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a compound semiconductor thin film manufacturing apparatus using sheet plasma.

Compound semiconductors include metal oxides, selenides, sulfides, and tellides, as well as intermetallic compounds of genus, genus and genus, or genus and genus, such as SiC,
These intermetallic compound semiconductors include GaAs, InP, GaP, InAs, and InSb, and these intermetallic compound semiconductors have large carrier mobility, large energy gaps, high operating temperature limits, and low reverse current as diodes. Therefore, it is used in parametric diodes, laser diodes, solar cells, etc.

Incidentally, such compound semiconductors are manufactured by various methods. For example, a molecular beam evaporation source is provided for each component element Am and Bn of the compound semiconductor AmBn to be produced, and each evaporation source is used to evaporate evaporation at a temperature maintained at the growth temperature. There is a method of growing a substrate by injecting a vapor molecule beam of each component element into the substrate, or an element whose adhesion probability is not 1 at the substrate temperature during growth (for example, Bn) among the component elements of the compound semiconductor AmBn to be generated. Some devices are known in which an evaporation source is provided to compensate for the deficiency caused by desorption of elements (elements) from the substrate surface. However, in such conventionally known devices, among the component elements of a compound semiconductor, elements whose adhesion probability is not 1 by normal thermal evaporation at the substrate temperature during growth are filled in the vacuum chamber during epitaxial growth, and molecules In beam evaporation source devices, the evaporated molecules condense on the vessel walls and inside the pump, causing contamination. Furthermore, when an ion beam is implanted from an evaporation source into a substrate, the ion beam tends to spread due to the influence of space charges, which not only makes it impossible to implant ions at a high density, but also causes contamination.

Meanwhile, research to create sheet plasma has progressed, and a technology that can form sheet plasma of desired dimensions has recently been developed. Simply put, this involves using permanent magnets to compress and expand plasma created by electric discharge in a magnetic field to form a sheet plasma with a desired width, thickness, and density.

Therefore, the present invention aims to provide a novel compound semiconductor thin film manufacturing apparatus using this sheet plasma.

In order to achieve this object, the compound semiconductor thin film production apparatus using sheet plasma according to the present invention provides a compound semiconductor component to be produced parallel to and close to the substrate and having a width covering a substantial portion of the substrate surface. A device for forming a sheet plasma containing elements that have a low adhesion probability at the growth temperature, a device for injecting molecular beams of other component elements into the substrate through the sheet plasma, and a device for connecting the sheet plasma and the substrate. The present invention is characterized by having a device that applies a voltage between the plasma sheets and extracts ions of component elements with low adhesion probability from the sheet plasma and injects them into the substrate together with molecular beams of other component elements.

The substrate is heated to maintain the growth temperature, and may be rotated, translated, or otherwise moved as necessary, or may be held stationary.

Furthermore, in this invention, the concept that the sheet plasma includes an element that has a probability of adhesion to the substrate of 1 or less at the growth temperature among the component elements of the compound semiconductor to be generated does not apply even if the sheet plasma is composed only of that element. It is recognized that other gas molecules may be included to facilitate plasma formation.

By configuring as follows, the present invention provides a new device that replaces conventionally known compound semiconductor manufacturing devices, and in this device, component elements with low adhesion probability are placed on sheet plasma and injected from near the substrate surface. Since the ions enter the substrate before being affected by the spread due to space charges, low-speed, high-density ion implantation is possible, and the growth chamber is not contaminated with elemental vapor that has a low probability of adhesion.
That is, in methods using ordinary molecular beam evaporation means, component elements with low adhesion probability tend to dissociate from the compound on the substrate or desorb from the surface of the element at the growth temperature, but in this invention Since the elements enter the sheet plasma containing the same elements, they can be ionized again in the sheet plasma and returned to the substrate. Therefore, depletion of component elements and contamination of the growth chamber due to desorption can be significantly improved.

The present invention will be further described below with reference to the accompanying drawings.

The drawing shows the device according to the invention in principle,
Reference numeral 1 denotes a substrate, which is heated to a growth temperature by a heating device not shown, and can be held stationary or in a rotational or translational state as described above. 2 is a sheet plasma forming device, which includes a sheet plasma generating section 2
a and a sheet plasma receiving section 2c that receives the sheet plasma 2b generated from the sheet plasma generating section 2a. sheet plasma 2b
is an element in the compound semiconductor AmBn to be generated that has a smaller probability of adhesion to the substrate at the growth temperature than 1.
contains Bn, and as shown in the figure, the substrate 1
parallel to and close to the surface of the sheet plasma 2b (for example, the distance between the boundary of the sheet plasma 2b and the substrate 1 is 2
mm to 30 mm). Further, a power source 3 is provided between the substrate 1 and the sheet plasma 2b to form an electric field for extracting ions (mainly ions of the component element Bn) from the sheet plasma 2b, and in this case, positive ions are extracted in the illustrated example. Anions can also be drawn out if necessary. With this configuration, the ions extracted from the sheet plasma 2b can reach the substrate 1 before the beam spreads due to the influence of space charges, and the ions extracted from the sheet plasma 2b can reach the substrate 1. For example, the acceleration energy when reaching
Any relatively low acceleration energy like 500ev can be obtained. It is difficult to obtain an acceleration energy of less than 200 ev with a method using an ion beam, but with sheet plasma, it is possible to easily create ions with low velocities, which is difficult with the ion beam method.

Further, in the drawing, 4 is a generation source of a molecular beam of the component element Am, and the molecular beam 4a from this generation source 4 preferably crosses the sheet plasma 2b from a direction perpendicular to the substrate 1 and enters the substrate 1. element when passing through the sheet plasma 2b.
Some of the Am vapor molecules are excited or ionized within the sheet plasma 2b and enter the substrate 1 together with other vapor molecules of the element Am having thermal kinetic energy. Note that the direction of the molecular beam 4a of the element Am does not necessarily have to be perpendicular to the substrate 1, and can be used as long as it is not extremely oblique.

Therefore, in the operation of the device of the present invention, component elements containing slightly excited or ionized particles are used.
The molecular beam 4a of Am and ions containing the component element Bn extracted from the sheet plasma 2b and accelerated by the action of the electric field existing between the substrate 1 and the sheet plasma 2b are simultaneously incident on the surface of the substrate 1. Since the surface of substrate 1 is kept at the growth temperature,
Both elements Am and Bn combine in a stoichiometric state,
The compound AmBn is formed on the surface.

[Brief explanation of drawings]

The drawing is a principle diagram of the compound semiconductor thin film manufacturing apparatus according to this invention. In the figure, 1: substrate, 2: sheet plasma generator, 4: molecular beam source.

Claims (1)

[Claims] 1. An apparatus for forming sheet plasma parallel to and close to the substrate and having a width covering a substantial portion of the substrate surface and containing elements that have a low adhesion probability at the growth temperature among the component elements of the compound semiconductor to be generated;
A device that injects molecular beams of other component elements through the sheet plasma and into the substrate, and a voltage is applied between the sheet plasma and the substrate to extract ions of component elements with low adhesion probability from the sheet plasma. 1. An apparatus for manufacturing a compound semiconductor thin film using sheet plasma, comprising: an apparatus for injecting a molecular beam of a component element into a substrate together with a molecular beam.