JPS5988820A - Compound semiconductor thin film manufacturing device utilizing sheet plasma - Google Patents

Abstract

PURPOSE:To realize low speed and high density ion implantation and protect the growth chamber from contamination by injecting ion from the area nearer to the substrate surface to an element having a low adhessive coefficient placed on the sheet plasma. CONSTITUTION:A sheet plasma forming apparatus 2 comprises a sheet plasma generator 2a and a sheet plasma receiver 2c. The sheet plasma 2b containes elements having adhessive coefficient less than 1 to a substrate 1 at a growth temperature among the compound semiconductors requested to grow up and is formed in parallel to the surface of substrate 1. With such structure, the ions extracted from the plasma 2b reaches the substrate 1 before it is subjected to spreading of beam due to the influence of space charges. Accordingly, ion implantation of low speed and high density can be realized and the growth chamber is protected from contamination by element vapor having low adhessive coefficient.

Description

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

In addition to metal oxides, selenides, sulfides, and tellurides, compound semiconductors include metal oxides, selenides, sulfides, and tellurides, as well as genus ITI, genus ITI, and genus ■.
Intermetallic compounds of the genus and genus eg, Sin.

These intermetallic compound semiconductors include GaAs, InP, GaP, InA, s, and In8b, and these intermetallic compound semiconductors have high 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.

By the way, such compound semiconductors can be manufactured by various methods, for example, compound semiconductors to be produced A m B
A molecular beam evaporation source is provided for each of the component elements Am and Bn of n, and vapor molecular beams of each component element are injected from each evaporation source into a substrate kept at the growth temperature. , compound semiconductor A to be produced
Among the constituent elements of mBn, a method is known in which an evaporation source is provided to compensate for the deficiency due to desorption from the substrate surface of an element (for example, Bn element) whose adhesion probability is / is not at the substrate temperature during growth.

However, in such a conventionally known method, among the component elements of a compound semiconductor, elements whose adhesion probability is not l by normal thermal evaporation at the substrate temperature during growth are filled in the vacuum chamber during epitaxial growth, and cannot be evaporated by molecular beam evaporation. In the source equipment, the evaporated molecules condense on the container 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 an apparatus for manufacturing a parent compound semiconductor thin film using this sheet plasma.

For this purpose, the apparatus according to the invention provides a method for producing a compound semiconductor parallel to and close to the substrate surface on which the compound semiconductor is to be produced.
an apparatus for forming a sheet plasma having a width that covers a substantial portion of a substrate surface and containing one of the component elements of a compound semiconductor to be generated that has a low adhesion probability at a growth temperature;
A device for injecting a molecular beam of the other component element into the base plate through the sheet plasma, and the one component element contained in the sheet plasma is extracted as ions and the molecules of the other component element are extracted. The beam is injected into the substrate along with the beam.

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

In addition, in this invention, the concept that the sheet plasma includes an element whose adhesion probability to the substrate at the growth temperature is / or less among the component elements of the compound semiconductor to be generated, even if the sheet plasma is composed only of that element, or It is recognized that other gas molecules may be included to facilitate plasma formation.

With this configuration, the present invention provides a new device that replaces conventionally known compound semiconductor manufacturing devices,
This device is configured so that component elements with low adhesion probability are placed on a sheet plasma and injected from near the substrate surface, so that they enter the substrate before being affected by space charge expansion, resulting in low-speed, high-speed injection. If high-density ion implantation becomes possible, the growth chamber will not be contaminated with elemental vapors that have a low probability of adhering to the river.

In other words, in a method using ordinary molecular beam evaporation means, component elements with a low adhesion probability dissociate from the compound on the substrate at the growth temperature and are likely to be desorbed from the surface of the element, but in this invention, the dissociation is prevented. Since the desorbed element enters the sheet plasma containing the same element, it can be returned to the substrate by etching 1M in the sheet plasma3, thus significantly improving the depletion of component elements and contamination of the growth chamber due to desorption. can do.

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; / is a substrate which is heated to the growth temperature in a heating device not shown and which can be held stationary or in rotational or translational movement as described above. λ is a sheet plasma forming apparatus, which is composed of a sheet plasma generating section 2a, a sheet plasma receiving section 2B that receives the sheet plasma generated from the sheet plasma generating section 2a, and a sheet plasma receiving section 2C; Among the compound semiconductors AmBn to be produced, it contains the element Bn, which has a smaller probability of adhering to the substrate at the growth temperature than /. The distance between the substrate and the substrate is, for example, λm to 30 cm.

Further, a power source 3 is provided between the substrate l 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. In this case, in the illustrated example, positive ions are extracted. It is also possible to draw out negative ions if necessary. With this configuration, the ions extracted from the sheet plasma column B can reach the substrate before the beam spreads due to the influence of space charges, and the ions extracted from the sheet plasma column B can reach the substrate. For example, the acceleration energy when reaching l is from rev! Any relatively low acceleration energy such as θθcV can be obtained. It is difficult to obtain acceleration energy of less than 200 e v' with methods using ion beams! , iI', but sheet plasma can easily produce low-velocity ions that are difficult to produce using ion beam methods.

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

Therefore, in the operation of the apparatus of the present invention, the partial beam 4ta of the component elements A and m containing particles that are ionized or ionized as slightly as r and the sheet plasma 2b are extracted from the substrate/and the sheet plasma 21. ) and ions containing the component element Bn are simultaneously incident on the surface of the substrate. Since the surface of the substrate is maintained at the growth temperature, both elements Am and Bn combine in a stoichiometric state, forming a compound A m B n on the surface.

[Brief explanation of drawings]

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

Claims (1)

[Claims] A device 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 one of the component elements of the compound semiconductor to be generated that has a low adhesion probability at the growth temperature. and a device for injecting a molecular beam of the other component element into the substrate through the sheet plasma, and extracting ions of one component element from the sheet plasma and injecting them into the substrate together with the molecular beam of the other component element. A compound semiconductor thin film manufacturing apparatus using sheet plasma, characterized in that it is configured to: