Apparatus and process for vacuum chemical epitaxy

Claim 1

A gas injection block for a vacuum chemical epitaxy apparatus comprising: a first mixing chamber; said first chamber having an inlet, said inlet suitable for passing metal-organic gaseous materials and n-type and p-type dopants into said chamber; a plurality of outlets from said first chamber, said outlets suitable for directing the flow of said metal-organic gases and n-type and p-type dopants toward a substrate; a second mixing chamber disposed below said first chamber, said second chamber having an inlet suitable for passing a metal-organic gaseous material and n-type and p-type dopants into said second chamber, said second chamber having a plurality of passages through said first chamber and an outlet for each passage, said outlets from said passages are in substantially the same plane with the outlets of said first chamber; and means for exhausting said metal-organic gaseous materials and said n-type and p-type dopants from said second chamber.

Claim 11

An apparatus for fabricating Group III-V semi-conductor layers, comprising: a vacuum chamber; a plurality of geometrically arranged Group III compound nozzles, said nozzles are located in substantially the same plane and capable of emitting a Group III gas in a direction of flow which is substantially perpendicular to a substrate located in a substrate plane spaced therefrom; a plurality of stacked mixing chambers connected to said nozzles, said chambers providing a mixing chamber for a particular Group III compound and at least one dopant, said plurality of mixing chambers comprising a first mixing chamber, said first chamber having an inlet, said inlet suitable for passing metal-organic gaseous materials and n-type and p-type dopants into said chamber, a plurality of outlets from said first chamber, said outlets suitable for directing the flow of said metal-organic gases and n-type and p-type dopants toward the substrate, a second mixing chamber disposed below said first chamber, said second chamber having an inlet suitable for passing a metal-organic gaseous material and n-type and p-type dopants into said second chamber, said second chamber having a plurality of passages through said first chamber and an outlet for each passage, said outlets from said passages being in substantially the same plane with the outlets of said first chamber; and means for exhausting said metal-organic gaseous materials and said n-type and p-type dopants from said second chamber; a substrate holder within said chamber, said holder oriented substantially perpendicular to the flow from said nozzles and at a distance from said plane of said nozzles so that the substrate plane is located at a distance less than the mean-free path of the Group III compound at the vacuum condition of the apparatus during the operation but large enough to obtain a uniform distribution of Group V compound at the substrate plane; a substrate heater, said substrate heater oriented to heat the side of the substrate opposite to the side facing the Group III compound; a source of Group V compound centrally located with respect to said Group III compound nozzle and dividing said group III nozzles into substantially uniform numbered groups of nozzles, said source of Group V compound being positioned to introduce a flow which is perpendicular to the flow of said Groups III compound, and into the flow of said Group III compound; means for exhausting non-reacted Group III and Group V compounds adjacent the edges of the chamber defined by the substrate plane; means for cooling the Group III compound mixing chamber and/or injection nozzles; means for thermally cracking the Group V compound prior to injection into the area between the substrate and the injection of the Group III compound; a zone to preheat the substrate prior to exposure to the Group III and V compounds; and a plurality of group III-V deposition zones, said zones capable of depositing a plurality of Group III-V compound compositional semiconductor layers.

Claim 12

An apparatus for fabricating Group III-V semi-conductor layers, comprising: a vacuum chamber; a plurality of geometrically arranged Group III compound nozzles, said nozzles are located in substantially the same plane and capable of emitting a Group III gas in a direction of flow which is substantially perpendicular to a substrate located in a substrate plane spaced therefrom; a plurality of stacked mixing chambers connected to said nozzles, said chambers providing a mixing chamber for a particular Group III compound and at least one dopant, said plurality of mixing chambers comprising a first mixing chamber, said first chamber having an inlet, said inlet suitable for passing metal-organic gaseous materials and n-type and p-type dopants into said chamber, a plurality of outlets from said first chamber, said outlets suitable for directing the flow of said metal-organic gases and n-type and p-type dopants toward the substrate, a second mixing chamber disposed below said first chamber, said second chamber having an inlet suitable for passing a metal-organic gaseous material and n-type and p-type dopants into said second chamber, said second chamber having a plurality of passages through said first chamber and an outlet for each passage, said outlets from said passages being in substantially the same plane with the outlets of said first chamber; and means for exhausting said metal-organic gaseous materials and said n-type and p-type dopants from said second chamber; a substrate holder within said chamber, said holder oriented substantially perpendicular to the flow from said nozzles and at a distance from said plane of said nozzles so that the substrate plane is located at a distance less than the mean-free path of the Group III compound at the vacuum condition of the apparatus during the operation but large enough to obtain a uniform distribution of Group V compound at the substrate plane; a substrate heater, said substrate heater oriented to heat the side of the substrate opposite to the side facing the Group III compound; a source of Group V compound centrally located with respect to said Group III compound nozzle and dividing said group III nozzles into substantially uniform numbered groups of nozzles, said source of Group V compound being positioned to introduce a flow which is perpendicular to the flow of said Groups III compound, and into the flow of said Group III compound; means for exhausting non-reacted Group III and Group V compounds adjacent the edges of the chamber defined by the substrate plane; means for cooling the Group III compound mixing chamber and/or injection nozzles; means for thermally cracking the Group V compound prior to injection into the area between the substrate and the injection of the Group III compound; a zone to preheat the substrate prior to exposure to the Group III and V compounds; and a plurality of group III-V deposition zones, said zones capable of depositing a plurality of Group III-V compound compositional semiconductor layers.