Abstract: The present invention discloses an X-ray imaging device comprising an X-ray absorber that comprises a plurality of semiconductor layers. The plurality of semiconductor layers comprise a substrate having a backside; and at least one absorption layer adapted to absorb at least one X-ray photon impinging on the at least one absorption layer that is adapted to correspondingly generate in response to the at least one impinging X-ray photon at least one electron-hole pair; and a readout unit, wherein the readout unit is operatively coupled to the X-ray absorber such to enable readout of the at least one electron-hole pair. Additional and alternative embodiments are described and claimed.

Abstract: Optical modulators include active quantum well structures coherent with pseudosubstrates comprising relaxed buffer layers on a silicon substrate. In a preferred method the active structures, consisting of Si1?x Gex barrier and well layers with different Ge contents x, are chosen in order to be strain compensated. The Ge content in the active structures may vary in a step-wise fashion along the growth direction or in the form of parabolas within the quantum well regions. Optical modulation may be achieved by a plurality of physical effects, such as the Quantum Confined or Optical Stark Effect, the Franz-Keldysh Effect, exciton quenching by hole injection, phase space filling, or temperature modulation. In a preferred method the modulator structures are grown epitaxially by low-energy plasma-enhanced chemical vapor deposition (LEPCVD).

Abstract: Method for forming a highly relaxed epitaxial semiconductor layer (52) with a thickness between 100 nm and 800 nm in a growth chamber includes four principle steps. In a first step, the method provides a substrate (51) in the growth chamber on a substrate carrier. In a second step, the method maintains a constant substrate temperature (TS) of the substrate (51) in a range between 350° C. and 500° C. In a third step, the method establishes a high-density, low-energy plasma in the growth chamber such that the substrate (51) is being exposed to the plasma. In a fourth step, the method directs Silane gas (SiH4) and Germane gas (GeH4) 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. The semiconductor layer (52) has a Germanium concentration x in a range between 0<x<50%.

Abstract: Method for making an InGaAs/GaAs quantum well laser (10) on a Silicon substrate (15.1). The method comprises the steps: Formation of a virtual Germanium substrate (15) on the Silicon substrate (15.1) by means of a low-energy plasma-enhanced chemical vapour deposition (LEPECVD). The virtual Germanium substrate (15) comprises a pure Germanium layer (15.3). Formation of a Gallium Arsenide structure on the virtual Germanium substrate (15) by means of a metal organic chemical vapour deposition process.

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.

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 crack-free GaAs layers suitable for high-efficiency solar cells, lasers and field effect transistors.

Abstract: Method for making an InGaAs/GaAs quantum well laser (10) on a Silicon substrate (15.1). The method comprises the steps: Formation of a virtual Germanium substrate (15) on the Silicon substrate (15.1) by means of a low-energy plasma-enhanced chemical vapour deposition (LEPECVD). The virtual Germanium substrate (15) comprises a pure Germanium layer (15.3). Formation of a Gallium Arsenide structure on the virtual Germanium substrate (15) by means of a metal organic chemical vapour deposition process.

Abstract: Method for forming a highly relaxed epitaxial semiconductor layer (52) with a thickness between 100 nm and 800 nm in a growth chamber. The method comprises the steps of: providing a substrate (51) in the growth chamber on a substrate carrier, maintaining a constant substrate temperature (TS) 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 (SiH4) and Germane gas (GeH4) 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<x<50%.

Abstract: Method for making a semiconductor structures comprising the steps:—forming a virtual substrate on a silicon substrate with a graded Si1-xGex layer and a non-graded Si1-xGex layer, using a high-density, low-energy plasma enhanced chemical vapor deposition (LEPECVD) process with a growth rate above 2 nm/s, a substrate temperature between 400° and 850° C., and a total reactive gas flow at the gas inlet between 5 sccm and 200 sccm;—forming an active region on the virtual substrate that comprises a Ge-channel and at least one modulation-doped layer using a low-density, low-energy plasma enhanced chemical vapor deposition (LEPECVD) process by introducing hydrogen (H2) into the growth chamber, maintaining a substrate temperature between 400° and 500° C., and by introducing a dopant gas in a pulsed manner into the growth chamber to provide for the modulation-doped layer.

Abstract: A method of fabricating semiconductor heterostructures including the steps of: (a) positioning a silicon wafer in a suitable environment and (b) processing the silicon substrate by applying several processing steps. A first optional processing step includes growing a graded buffer layer on a silicon substrate by low-energy plasma-enhanced chemical vapor deposition (LEPECVD). A second processing step includes growing a constant composition buffer layer by LEPECVD. A third processing step includes subjecting the surface of the strain-relaxed buffer layer to a deposition process for a period of time and under prescribed conditions, in order to grow at least one additional layer. Subsequently, devices may be processed from the grown layer stack by using a prescribed sequence of steps including non-standard CMOS processes.

Abstract: A system and a method produce workpieces coated by PECVD with a quality sufficient for epitaxy. Included are a vacuum recipient, a plasma discharge source operationally connected to the vacuum recipient and a workpiece holder within the vacuum recipient, said plasma discharge source generating on said workpiece holder ions with an energy of below 15 eV. The plasma discharge source can be a low-voltage plasma discharge source in which at least one cathode is arranged within a cathode chamber coupled to the vacuum recipient by a diaphragm.

Abstract: The method is characterized in that layers of sufficient quality for epitaxy are placed on workpieces, at a considerably increased deposition rate. To this end, instead of a UHV-CVD or ECR-CVD method, for example, a PECVD method is used by means of a DC plasma discharge.