Leland Stanford Junior University

Canon Kabushiki Kaisha

The University of Texas System

Other

Nec Corporation

Krishna Chandra Saraswat

Chi On Chui

Takao Yonehara

Ammar Munir Nayfeh

Mehrdad M Moslehi

Donald S Gardner

Troy W Barbee, Jr

Yeul Na

Aneesh Nainani

Butrus Thomas Khuri-Yakub

Munehiro Tada

Pawan Kapur

Jelena Vuckovic

Paul C McIntyre

Yong J Lee

Tejas Krishnamohan

B T Khuri-Yakub

Baylor B Triplett

Devanand S Sukhdeo

Mehmet Günhan Ertosun

Shashank Gupta

Koosha Nassiri Nazif

Raisul Islam

Jin-Hong Park

Sanjay Bhardwaj

Donguk Nam

Ashish Pal

Tsu-Jae King

Jan A Petykiewicz

Chi Y Fu

Tandem solar cell configurations are provided where at least one of the cells is a metal chalcogenide cell. A four-terminal tandem solar cell configuration has two electrically independent solar cells stacked on each other. A two-terminal solar cell configuration has two electrically coupled solar cells (same current through both cells) stacked on each other. Carrier selective contacts can be used to make contact to the metal chalcogenide cell (s) to alleviate the troublesome Fermi level pinning issue. Carrier-selective contacts can also remove the need to provide doping of the metal chalcogenide. Doping of the metal chalcogenide can be provided by charge transfer. These two ideas can be practiced independently or together in any combination.

Tandem solar cells having a top or bottom metal chalcogenide cell

A crossed nanobeam structure for strain engineering in semiconductor devices is provided. For example, such a structure can be used for a low-threshold germanium laser. While the photonic crystal nanobeam enables light confinement in a subwavelength volume with small optical loss, another crossing nanobeam induces high tensile strain in the small region where the optical mode is tightly confined. As maintaining a small optical loss and a high tensile strain reduces the required pumping for achieving net optical gain beyond cavity losses, this technique can be used to develop an extremely low-threshold Ge laser source. Moreover, the structure can be easily integrated into electronic and photonic circuits.

Crossed nanobeam structure for a low-threshold germanium laser

A depletion-mode phototransitor is disclosed. The phototransistor having a substrate, a gate, a source, a drain and a channel. The source, drain and channel are doped to be the same type of semiconductor. The substrate can be made of silicon and/or germanium. The gate can be made of either aluminum or polysilicon.

Depletion-mode field-effect transistor-based phototransistor

Various aspects of the invention are directed to memory circuits and their implementation. According to an example embodiment, an apparatus includes a channel region between raised source and drain regions which are configured and arranged with respective bandgap offsets relative to the channel region to confine carriers in the channel region. The apparatus also includes front and back gates respectively separated from the channel region by gate dielectrics. The raised source and drain regions have respective portions laterally adjacent the front gate and adjacent the channel region. Carriers are stored in the channel region via application of voltage(s) to the front and back gates, and relative to bias(es) at the source and drain regions.

Transistor-based apparatuses, systems and methods

In accordance with one or more embodiments, an apparatus and method involves a channel region, barrier layers separated by the channel region and a dielectric on one of the barrier layers. The barrier layers have band gaps that are different than a band gap of the channel region, and confine both electrons and holes in the channel region. A gate electrode applies electric field to the channel region via the dielectric. In various contexts, the apparatus and method are amenable to implementation for both electron-based and hole-based implementations, such as for nmos, pmos, and cmos applications.

Heterostructure field effect transistor with same channel and barrier configuration for PMOS and NMOS

Depletion-mode field-effect transistor-based phototransitor

Data is stored in a quantum-well type structure with double gate control. According to an example embodiment, a transistor-based data storage circuit includes a gate, a back gate and a semiconductor channel between the gate and the back gate. Carriers are stored in a storage pocket structure in the channel, in response to biases applied to the gate and back gate. Current passing through the channel is sensed and used to detect the stored carriers and, correspondingly, a memory state of the storage circuit.

Memory circuit with quantum well-type carrier storage

This invention provides a method of forming semiconductor films on dielectrics at temperatures below 400&#xb0; C. Semiconductor films are required for thin film transistors (TFTs), on-chip sensors, on-chip micro-electromechanical systems (MEMS) and monolithic 3D-integrated circuits. For these applications, it is advantageous to form the semiconductor films below 400&#xb0; C. because higher temperatures are likely to destroy any underlying devices and/or substrates. This invention successfully achieves low temperature growth of germanium films using diboran. First, diboran gas is supplied into a reaction chamber at a temperature below 400&#xb0; C. The diboran decomposes itself at the given temperature and decomposed boron is attached to the surface of a dielectric, for e.g., SiO, forming a nucleation site and/or a seed layer. Second, source gases for semiconductor film formation, for e.g., SiH, GeH, etc., are supplied into the chamber, thereby forming a semiconductor film.

Method of forming of a semiconductor film, method of manufacture of a semiconductor device and a semiconductor device

Germanium circuit-type structures are facilitated. In one example embodiment, a multi-step growth and anneal process is implemented to grow Germanium (Ge) containing material, such as heteroepitaxial-Germanium, on a substrate including Silicon (Si) or Silicon-containing material. In certain applications, defects are generally confined near a Silicon/Germanium interface, with defect threading to an upper surface of the Germanium containing material generally being inhibited. These approaches are applicable to a variety of devices including Germanium MOS capacitors, pMOSFETs and optoelectronic devices.

Germanium substrate-type materials and approach therefor

Various semiconductor devices and methods of manufacture are employed. According to an example embodiment of the present invention, a MOS-compatible semiconductor device exhibits high channel mobility and low leakage. The device includes a channel region having a high-mobility strained material layer and a tunneling mitigation layer on the strained material layer to mitigate tunnel leakage. The strained material has a lattice structure that is strained to match the lattice structure of the tunneling mitigation layer. An insulator layer is on the tunneling mitigation layer, and an electrode is over the insulator and adapted to apply a voltage bias to the channel region to switch the device between conductive and nonconductive states. Current is transported in the conductive state as predominantly facilitated via the mobility of the strained material layer, and wherein tunneling current in the nonconductive state is mitigated by the tunneling mitigation layer.

Semiconductor device with high on current and low leakage

Excellent capacitor-voltage characteristics with near-ideal hysteresis are realized in a capacitive-like structure that uses an electrode substrate-type material with a high-k dielectric layer having a thickness of a few-to-several Angstroms capacitance-based SiOequivalent ('T'). According to one particular example embodiment, a semiconductor device structure has an electrode substrate-type material having a Germanium-rich surface material. The electrode substrate-type material is processed to provide this particular electrode surface material in a form that is thermodynamically stable with a high-k dielectric material. A dielectric layer is then formed over the electrode surface material with the high-k dielectric material at a surface that faces, lies against and is thermodynamically stable with the electrode surface material.

High-k dielectric for thermodynamically-stable substrate-type materials

Layered structures (e.g., Al-Si/Ti/Al-Si . . . ) and homogeneous alloys of aluminum and aluminum/1 at. % silicon with titanium and tungsten and other refractory metals have been found to significantly reduce hillock densities in the films when small amounts of titanium or tungsten are homogeneously added. However, the resistivity of the films can become excessive. In addition, a new type of low density hillock can form. Layering of the films eliminates all hillocks and results in films of low resistivity. Such layered and homogeneous films made with Al-Si and Ti were found to be dry etchable. Electrical shorts in test structures with two levels of metal and LPCVD SiO as an interlayer dielectric have been characterized and layered films using Al-Si and Ti gave excellent results.

Layered and homogeneous films of aluminum and aluminum/silicon with titanium and tungsten for multilevel interconnects

An acoustic temperature and/or film thickness monitoring system for semiconductor wafers in which the velocity of acoustic waves in the wafer is employed to measure temperature and/or thickness.

Acoustic temperature and film thickness monitor and method

Growing community of inventors

Saratoga, CA, United States of America

Krishna Chandra Saraswat