Abstract:
A method of growing a germanium (Ge) epitaxial thin film having negative photoconductance characteristics and a photodiode using the same are provided. The method of growing the germanium (Ge) epitaxial thin film includes growing a germanium (Ge) thin film on a silicon substrate at a low temperature, raising the temperature to grow the germanium (Ge) thin film, and growing the germanium (Ge) thin film at a high temperature, wherein each stage of growth is performed using reduced pressure chemical vapor deposition (RPCVD). The three-stage growth method enables formation of a germanium (Ge) epitaxial thin film characterized by alleviated stress on a substrate, a lowered penetrating dislocation density, and reduced surface roughness.
Abstract:
Provided is a method of forming optical waveguide. The method includes forming a trench on a semiconductor substrate to define an active portion, and partially oxidizing the active portion. An non-oxidized portion of the active portion is included in a core through which an optical signal passes, and an oxidized portion of the active portion is included in a cladding.
Abstract:
Provided is a method of growing a pure germanium (Ge) thin film with low threading dislocation density using reduced pressure chemical vapor deposition (RPCVD), which includes growing a Ge thin film on a silicon (Si) substrate at a low temperature, performing real-time annealing for a short period of time, and growing the annealed Ge thin film at a high temperature. The grown Ge single crystal thin film can overcome conventional problems of generation of a Si—Ge layer due to Si diffusion, and propagation of misfit dislocation to a high-temperature Ge thin film.
Abstract:
Provided is a semiconductor and a method for forming the same. The method includes forming a buried insulating layer locally in a substrate. The substrate is etched to form an opening exposing the buried insulating layer, and a silicon pattern spaced in at least one direction from the substrate is formed on the buried insulating layer. A first insulating layer is formed to enclose the silicon pattern.
Abstract:
Provided is a semiconductor and a method for forming the same. The method includes forming a buried insulating layer locally in a substrate. The substrate is etched to form an opening exposing the buried insulating layer, and a silicon pattern spaced in at least one direction from the substrate is formed on the buried insulating layer. A first insulating layer is formed to enclose the silicon pattern.
Abstract:
Provided is a method of fabricating a semiconductor device. The method includes forming a first layer, a second layer, an ion implantation layer between the first and second layers, and an anti-oxidation layer on the second layer, and performing a heat treating process to form an insulating layer between the first and second layers while preventing loss of the second layer using the anti-oxidation layer.
Abstract:
Provided is a semiconductor and a method for forming the same. The method includes forming a buried insulating layer locally in a substrate. The substrate is etched to form an opening exposing the buried insulating layer, and a silicon pattern spaced in at least one direction from the substrate is formed on the buried insulating layer. A first insulating layer is formed to enclose the silicon pattern.
Abstract:
Provided are a stamper fabricated by using an embossing master and a focusing grating coupler fabricated by using the stamper, which is applicable to a subminiature pickup head for a mobile optic disk, whereby it is possible to reduce a weight and a volume of the pickup head with a simple process and low cost and to apply for mass production.
Abstract:
Provided is a focusing waveguide grating coupler using a leaky mode which can form single output beam while relieving the dependency on manufacturing processes. The focusing waveguide grating coupler of the present research includes: a substrate having a first refraction index n1; a first core layer having a second refraction index n2, the first core layer being formed on the substrate; a second core layer having a third refraction index n3, the second core layer being formed on the first core layer apart from the first core layer with a space d in between; a first cladding layer having a fourth refraction index n4, the first cladding layer being formed on the second core layer; a second cladding layer having a fifth refraction index n5, the second cladding layer being formed on the first cladding layer and inserted between the first core layer and the second core layer; and a Fresnel lens positioned on the second cladding layer, wherein the refractive indexes satisfy conditions of n5>(n2, n3)>n1 and n5>n4; and light inputted through the first and second core layers to the Fresnel lens as radiated leaky beam by a leaky mode formed according to the conditions, and the leaky beam forms an optical focus by performing single directional coupling.
Abstract:
Provided is a focusing waveguide grating coupler using a leaky mode which can form single output beam while relieving the dependency on manufacturing processes. The focusing waveguide grating coupler of the present research includes: a substrate having a first refraction index n1; a first core layer having a second refraction index n2, the first core layer being formed on the substrate; a second core layer having a third refraction index n3, the second core layer being formed on the first core layer apart from the first core layer with a space d in between; a first cladding layer having a fourth refraction index n4, the first cladding layer being formed on the second core layer; a second cladding layer having a fifth refraction index n5, the second cladding layer being formed on the first cladding layer and inserted between the first core layer and the second core layer; and a Fresnel lens positioned on the second cladding layer, wherein the refractive indexes satisfy conditions of n5>(n2, n3)>n1 and n5>n4; and light inputted through the first and second core layers to the Fresnel lens as radiated leaky beam by a leaky mode formed according to the conditions, and the leaky beam forms an optical focus by performing single directional coupling.