Abstract: The disclosure provides a method for preparing a self-aligned surface channel field effect transistor, and provides a power device. The method includes the following steps: depositing a first metal mask layer; preparing a first photoresist layer; forming a source area pattern and a drain area pattern; depositing a source metal layer and a drain metal layer on the source area pattern and the drain area pattern; peeling off and removing the first photoresist layer; depositing a second metal mask layer; preparing a second photoresist layer, and forming at least one gate area pattern closer toward the source metal layer by performing exposure and development; removing the first metal mask layer and the second metal mask layer between the source metal layer and the drain metal layer by a wet corrosion; depositing a gate metal layer on the gate area pattern; and peeling off and removing the second photoresist layer.

Abstract: Disclosed are a preparation method for a diamond-based field effect transistor and a field effect transistor, relating to the technical field of semi-conductors.

Abstract: Disclosed are a preparation method for a diamond-based field effect transistor and a field effect transistor, relating to the technical field of semi-conductors.

Abstract: The disclosure provides a method for preparing a self-aligned surface channel field effect transistor, and provides a power device. The method includes the following steps: depositing a first metal mask layer; preparing a first photoresist layer; forming a source area pattern and a drain area pattern; depositing a source metal layer and a drain metal layer on the source area pattern and the drain area pattern; peeling off and removing the first photoresist layer; depositing a second metal mask layer; preparing a second photoresist layer, and forming at least one gate area pattern closer toward the source metal layer by performing exposure and development; removing the first metal mask layer and the second metal mask layer between the source metal layer and the drain metal layer by a wet corrosion; depositing a gate metal layer on the gate area pattern; and peeling off and removing the second photoresist layer.

Abstract: The present application discloses a semiconductor device and a method for forming a p-type conductive channel in a diamond using an abrupt heterojunction, which pertain to the technical field of fabrication of semiconductor devices. The method includes: forming a diamond layer on a substrate; forming one or multiple layers of a heterogeneous elementary substance or compound having an acceptor characteristic on an upper surface of the diamond layer; forming a heterojunction at an interface between the diamond layer and an acceptor layer; forming two-dimensional hole gas at one side of the diamond layer with a distance of 10 nm-20 nm away from the heterojunction; and using the two-dimensional hole gas as a p-type conductive channel. The method enables a concentration and a mobility of carriers to maintain stable at a temperature range of 0° C.-1000° C., thereby realizing normal operation of the diamond device at high temperature environment.

Abstract: The present application discloses a semiconductor device and a method for forming an n-type conductive channel in a diamond using a heterojunction, which pertain to the technical field of fabrication of semiconductor devices. The method comprises: forming a diamond layer on a substrate; and depositing a ternary compound having a donor characteristic and graded components on an upper surface of the diamond layer to form a first donor layer, forming a graded heterojunction at an interface between the diamond layer and the first donor layer, forming two-dimensional electron gas at one side of the diamond layer adjacent to the graded heterojunction, and using the two-dimensional electron gas as the n-type conductive channel. The method enables a concentration and a mobility of carriers in the n-type diamond channel to reach 1013 cm?2 and 2000 cm2/V·s respectively.

Abstract: The present application discloses a semiconductor device and a method for forming a p-type conductive channel in a diamond using an abrupt heterojunction, which pertain to the technical field of fabrication of semiconductor devices. The method includes: forming a diamond layer on a substrate; forming one or multiple layers of a heterogeneous elementary substance or compound having an acceptor characteristic on an upper surface of the diamond layer; forming a heterojunction at an interface between the diamond layer and an acceptor layer; forming two-dimensional hole gas at one side of the diamond layer with a distance of 10 nm-20 nm away from the heterojunction; and using the two-dimensional hole gas as a p-type conductive channel. The method enables a concentration and a mobility of carriers to maintain stable at a temperature range of 0° C.-1000° C., thereby realizing normal operation of the diamond device at high temperature environment.

Abstract: The present application discloses a semiconductor device and a method for forming an n-type conductive channel in a diamond using a heterojunction, which pertain to the technical field of fabrication of semiconductor devices. The method comprises: forming a diamond layer on a substrate; and depositing a ternary compound having a donor characteristic and graded components on an upper surface of the diamond layer to form a first donor layer, forming a graded heterojunction at an interface between the diamond layer and the first donor layer, forming two-dimensional electron gas at one side of the diamond layer adjacent to the graded heterojunction, and using the two-dimensional electron gas as the n-type conductive channel. The method enables a concentration and a mobility of carriers in the n-type diamond channel to reach 1013 cm?2 and 2000 cm2/V·s respectively.

Abstract: The present invention is a fast indexing technique that builds an indexing structure based on multi-level key ranges typically for large data storage systems. The invention is explained based on the B+-tree. It is designed to reside in main memory. Point searches and range searches are helped by early termination of searches for non-existent data. Range searches can be processed depth-first or breath-first. One group of multiple searches can be processed with one pass on the indexing structure to minimize total cost. Implementation options and strategies are explained to show the flexibility of this invention for easy adaption and high efficiency. Each branch of any level has exact and clear key boundaries, so that it is very easy to build or cache partial index for various purposes. The inventive indexing structure can be tuned to speed up queries directed at popular ranges of index or index ranges of particular interest to the user.

Abstract: A method and apparatus for implementation in a database management system transforms high-dimensional data points to a single-dimensional space so that single-dimensional values can be used as representative index keys for high-dimensional data points and a single-dimensional index structure can be employed to index the transformed values. Upon achieving transformed values, known single-dimensional indexing structures can be employed. To achieve transformation from high-dimensions to a single-dimension, attribute values of a data item, each representing a different dimension, are mapped into a range and an integer value is assigned to each dimension. Either the minimum or maximum dimension value for the multi-dimensional data item is selected, and the minimum or maximum dimensional value is added to the integer value.

Abstract: We disclose a transformation-based method for indexing high-dimensional data to support similarity search. The method, iDistance, partitions the data into clusters either based on some clustering strategies or simple data space partitioning strategies. The data in each cluster can be described based on their similarity with respect to a reference point, and hence they can be transformed into a single dimensional space based on such relative similarity. This allows us to index the data points using a B+-tree structure and perform similarity search using range search strategy. As such, the method is well suited for integration into existing DBMSs. We also study two data partitioning strategies, and several methods on selection of reference points. We conducted extensive experiments to evaluate iDistance, and our results demonstrate its effectiveness.

Abstract: A method and apparatus for implementation in a database management system transforms high-dimensional data points to a single-dimensional space so that single-dimensional values can be used as representative index keys for high-dimensional data points and a single-dimensional index structure can be employed to index the transformed values. Upon achieving transformed values, known single-dimensional indexing structures can be employed. To achieve transformation from high-dimensions to a single-dimension, attribute values of a data item, each representing a different dimension, are mapped into a range and an integer value is assigned to each dimension. Either the minimum or maximum dimension value for the multi-dimensional data item is selected, and the minimum or maximum dimensional value is added to the integer value.

Abstract: We disclose a transformation-based method for indexing high-dimensional data to support similarity search. The method, iDistance, partitions the data into clusters either based on some clustering strategies or simple data space partitioning strategies. The data in each cluster can be described based on their similarity with respect to a reference point, and hence they can be transformed into a single dimensional space based on such relative similarity. This allows us to index the data points using a B+-tree structure and perform similarity search using range search strategy. As such, the method is well suited for integration into existing DBMSs. We also study two data partitioning strategies, and several methods on selection of reference points. We conducted extensive experiments to evaluate iDistance, and our results demonstrate its effectiveness.