A known method of manufacturing, for example, lasers comprises the deposition, on a substrate (1), of semiconductor layers from a gas (3) which includes at least two reactive components, such as TMG and arsine to form GaAs. The substrates (1) are arranged, within a reactor (10), on a supporting plate (2), heated and, preferably, rotated about their own center and the center of the supporting plate (2). Arsine (4) is supplied centrally above the supporting plate (2), and TMG (5) is supplied directly around said arsine, but separated therefrom, said TMG terminating at a larger distance from the supporting plate (2). These gases (4, 5) then flow sideways across the supporting plate (2) covered with substrates (1) and are discharged at the side thereof. Such a method results in a good homogeneity of the properties of the deposited semiconductor layer, which is crucial to many semiconductor devices. However, the spread, particularly, in the thickness but also in the composition, both within a substrate (1) and between two or more substrates (1) within a single deposition, as well as between different depositions, leaves to be desired. In accordance with the invention, the TMG gas flow (5) is built up of n, n being greater than or equal to two, individual gas sub-flows (5A), each supplying 1/n th part of the second gas flow (5) and being supplied symmetrically with respect to the center of the supporting plate (2). Surprisingly, it has been found that this results in a substantial improvement of the above-mentioned homogeneities, in particular when the deposited semiconductor layer is very thin. Preferably, the TMG gas flow (5) is built up of an even number, preferably 4, gas sub-flows (5A). For this purpose, a device in accordance with the invention is equipped with a corresponding number of supply tubes (6). Use can further advantageously be made of a mixing chamber (13) for the gas sub-flows (5A) from which, for example at least twice as many, further gas sub-flows (5B) flow towards the supporting plate (2).

The present invention is an apparatus for distributing reactant gases across the substrate mounted in a reaction chamber. The apparatus is capable of being utilized in both vapor deposition and etching processes. The apparatus substantially compensates for the problem of non-uniformity of vapor deposition and etching at the edges of the wafers caused by gas depletion. A gas distribution plate having a plurality of apertures extending therethrough is attached to an interior surface of the reaction chamber. At least one vacuum sealed partition is disposed between a surface of the gas distribution plate and the interior surface of the chamber. The partition separates the space between the plate and reaction chamber into gas distribution zones. A gas inlet is connected to each gas distribution zone. Each gas inlet line has at least one mass flow controller which regulates the flow of gas to each gas distribution zone. The mass flow controllers are utilized to ensure a uniform rate of chemical vapor deposition or etching across the surface of the substrate.

The invention relates to a gaseous phase chemical treatment reactor for wafers. The aim of the invention is to produce a reactor in which only the face of the wafer to be treated is in fact treated. This aim is achieved with the aid of a reactor comprising at least one treatment chamber (19) located within a main chamber (9) and connected by one of its ends to means (17) for injecting a treatment gas onto a wafer (1) and by its other end to a means (15) for securing said wafer, in that the latter is gripped between a heating susceptor or base (13) and the retaining means (15) in such a way as to seal said treatment chamber (19) and maintain within the latter a pressure below that of the main chamber (9). The invention more particularly relates to reactors for depositing tungsten on silicon wafers.

A cage for low pressure chemical depositions reactors to provide for the relatively uniform deposition of silicon dioxide and phosphorus doped polysilicon along the length of a reactor by the chemical decomposition of silane. The cage is comprised of an open structure, generally surrounding semiconductor wafers supported on boats within the reactor, so as to discourage preferential deposition rates adjacent the silane inlet region of the reactor, and to encourage a more uniform distribution of the decomposable gas along the reactor length to effect more uniform deposition rates than previously accomplished. The open structure helps to quickly develop the flow along the reactor so that the flow quickly stabilizes adjacent the inlet end of the reactor and remains substantially uniform thereafter. Longitudinal alignment of the major elements of the cage provides continuous flow surfaces along the length of the reactor.

A CVD method including the steps of: setting a semiconductor wafer on a heating stage within a CVD reaction chamber; and emitting CVD reaction gas towards at least the central major region of the wafer from a first gas blowing region of a gas head provided opposing the wafer and having a plurality of gas blowing regions separated from each other, and simultaneously emitting inert gas towards the peripheral region of the wafer from a second gas blowing region of the gas head, while maintaining the temperature of the wafer at a predetermined temperature, and while maintaining the pressure of the CVD reaction chamber within a range from 100 Torr to atmospheric pressure; whereby a CVD film of high quality can be formed in uniform thickness on the wafer, and the consumed amount of reaction gas and the amount of undesirable precipitated particles can be reduced.