Abstract:
Method for forming a highly relaxed epitaxial semiconductor layer (52) with a thickness between 100nm and 800nm in a growth chamber. The method comprises the steps: - providing a substrate (51) in the growth chamber on a substrate carrier,- maintaining a constant substrate temperature (T s ) of the substrate (51) in a range between 350°C and 500°C,- establishing a high-density, low-energy plasma in the growth chamber such that the substrate (51) is being exposed to the plasma,- directing Silane gas (SiH 4 ) and Germane gas (GeH 4 ) through the gas inlet into the growth chamber, the flow rates of the Silane gas and the Germane gas being adjusted in order to form said semiconductor layer (52) by means of vapor deposition with a growth rate in a range between 1 and 10 nm/s, said semiconductor layer (52) having a Germanium concentration x in a range between 0
Abstract:
An apparatus and process for fast epitaxial deposition of compound semiconductor layers includes a low-energy, high-density plasma generating apparatus for plasma enhanced vapor phase epitaxy. The process provides in one step, combining one or more metal vapors with gases of non-metallic elements in a deposition chamber. Then highly activating the gases in the presence of a dense, low-energy plasma. Concurrently reacting the metal vapor with the highly activated gases and depositing the reaction product on a heated substrate in communication with a support immersed in the plasma, to form a semiconductor layer on the substrate. The process is carbon-free and especially suited for epitaxial growth of nitride semiconductors at growth rates up to 10 nm/s and substrate temperatures below 1000°C on large-area silicon substrates. The process requires neither carbon-containing gases nor gases releasing hydrogen, and in the absence of toxic carrier or reagent gases, is environment friendly.
Abstract:
Relaxed germanium buffer layers can be grown economically on misoriented silicon wafers by low-energy plasma-enhanced chemical vapor deposition. In conjunction with thermal annealing and/or patterning, the buffer layers can serve as high-quality virtual substrates for the growth of crackfree GaAs layers suitable for high-efficiency solar cells, lasers and field effect transistors.
Abstract:
Method for making semiconductor structures comprising the steps: - forming a virtual substrate on a silicon substrate with a graded Si>1-x x 1-x x 2
Abstract:
A ground covering comprises a mat-like base (1) which can be placed on the underlying ground (7) and which is provided with apertures (3). A granular bulk material, which forms the walk-on surface of the ground covering, can be applied to this mat-like base (1). The mat-like base (1) is provided with studs (6) which are mounted onto the webs (4) bounding the apertures (3) and which, with the mat-like base (1) placed on the underlying ground (7), are oriented upwardly against the granular bulk material. The studs (6) each form the corner points of a substantially equilateral polygon. The bulk material consists of pieces of stone (9) which have a particle size B which corresponds at least to half the length A of one side of the polygon. A uniform and hard-wearing ground covering is thereby obtained.
Abstract:
An apparatus and process for fast epitaxial deposition of compound semiconductor layers includes a low-energy, high-density plasma generating apparatus for plasma enhanced vapor phase epitaxy. The process provides in one step, combining one or more metal vapors with gases of non-metallic elements in a deposition chamber. Then highly activating the gases in the presence of a dense, low-energy plasma. Concurrently reacting the metal vapor with the highly activated gases and depositing the reaction product on a heated substrate in communication with a support immersed in the plasma, to form a semiconductor layer on the substrate. The process is carbon-free and especially suited for epitaxial growth of nitride semiconductors at growth rates up to 10 nm/s and substrate temperatures below 1000°C on large-area silicon substrates. The process requires neither carbon-containing gases nor gases releasing hydrogen, and in the absence of toxic carrier or reagent gases, is environment friendly.
Abstract:
An apparatus and process for fast epitaxial deposition of compound semiconductor layers includes a low-energy, high-density plasma generating apparatus for plasma enhanced vapor phase epitaxy. The process provides in one step, combining one or more metal vapors with gases of non-metallic elements in a deposition chamber. Then highly activating the gases in the presence of a dense, low-energy plasma. Concurrently reacting the metal vapor with the highly activated gases and depositing the reaction product on a heated substrate in communication with a support immersed in the plasma, to form a semiconductor layer on the substrate. The process is carbon-free and especially suited for epitaxial growth of nitride semiconductors at growth rates up to 10 nm/s and substrate temperatures below 1000°C on large-area silicon substrates. The process requires neither carbon-containing gases nor gases releasing hydrogen, and in the absence of toxic carrier or reagent gases, is environment friendly.
Abstract:
A system (10) for low-energy plasma-enhanced chemical vapor deposition comprising plasma source (100), deposition chamber (200) and gas distribution system (300) for semiconductor epitaxy on substrates up to 300 mm in size is described. The system (10) allows for fast switching from high to low deposition rates, and film thickness control at the monolayer level. It incorporates chamber self-cleaning and the provisions for selective epitaxial growth. The system (10) contains a broad-area plasma source (100) which can be used also in other applications, such as low-energy ion implantation and plasma treatment of surfaces.