Lucent Technologies Inc.

American Telephone & Telegraph Co., At&t Bell Laboratories

Bell Telephone Laboratories

Other

At+t Corp.

At&t Bell Laboratories

Agere Systems Guardian Corp.

Barry Franklin Levine

Clyde G Bethea

Gordon Albert Thomas

Christopher James Pinzone

Roger J Malik

Sanghee Park Hui

Federico Capasso

Won-Tien Tsang

Albert Lee Hutchinson

Ralph A Logan

Glenn B Alers

Daniel Brasen

Robert McLemore Fleming

Ronald H Willens

John F Walker

Ghulam Hasnain

Kwong-Kit Choi

Gabby Sarusi

Robert T Lynch

Carl D Thurmond

This invention is predicated upon applicants'discovery that the quality of high performance heterointerface devices having diffused junction depends significantly on the rate of cooling after diffusing the junctions. Use of the method to fabricate a high performance photodiode is described.

Method of fabricating heterointerface devices having diffused junctions

A process for device fabrication is disclosed in which two substrates having different crystal lattices are bound together. In the process the substrate surfaces are placed in physical contact with each other. A flexible membrane is placed in physical contact with a surface of one of the substrates. Pneumatic force is applied to the flexible membrane. The duration of the contact and the pressure of the contact are selected to facilitate a bond between the two substrate surfaces that results from attractive Van der Waals' forces between the two surfaces. The bulk of one of the substrates is then typically removed. Thereafter, the bonded surfaces are heated to a high temperature to effect a permanent bond.

Method for attractive bonding of two crystalline substrates

A process for device fabrication is disclosed in which two substrates having different crystal lattices are bound together. In the process the substrate surfaces are thoroughly cleaned and placed in physical contact with each other. The duration of the contact and the pressure of the contact are selected to facilitate a bond between the two substrate surfaces that results from attractive Van der Waals' forces between the two surfaces. The bonded substrates are heated to a moderate temperature to effect escape of gases which may be entrapped by the substrates. The bulk of one of the substrates is then typically removed. The substrates can be heated again to a moderate temperature to effect removal of any gases remaining entrapped on the substrates. Thereafter, the bonded surfaces are heated to a high temperature to effect a permanent bond.

Method for bonding two crystalline substrates together

Apparatus for processing a silicon workpiece uses reflected UV light to measure and control the workpiece temperature. A linearly polarized beam including UV light is directed onto a silicon surface to produce a reflected beam. The reflected beam is cross-polarized to null out much of the light, and the resulting residual reflectivity spectrum is determined. The temperature is determined from the characteristics of this spectrum. A workpiece heating station uses this measuring technique to accurately control the temperature of a silicon workpiece and temperature-dependent processing over a wide range of processing temperatures, including temperatures below 500.degree. C.

Apparatus for processing silicon devices with improved temperature

A process for device fabrication is disclosed in which two substrates having different crystal lattices are bound together. In the process a layer of material that has a crystal lattice similar to the crystal lattices of the first substrate is formed on the surface of the second substrate. The thickness of the layer is about 1 nm to about 2 nm. The layer of material is then bound to the surface of the first substrate.

Process for bonding crystalline substrates with different crystal

Si-based photodetectors according to the invention can have high speed (e.g.,.gtoreq.1 Gb/s) and high efficiency (e.g.,&gt;20%). The detectors include a relatively thin (e.g.,&lt;0.5.alpha..sup.-1, where .alpha..sup.-1 is the absorption length in Si of the relevant radiation) crystalline Si layer on a dielectric (typically SiO.sub.2) layer, with appropriate contacts on the Si layer. Significantly, the surface of the Si layer is textured such that the radiation that is incident on the surface and transmitted into the Si layer has substantially random direction. The randomization of the propagation direction results in substantial trapping of the radiation in the Si layer, with attendant increased effective propagation length in the Si. Detectors according to the invention advantageously are integrated with the associated circuitry on a Si chip, typically forming an array of detectors.

Article comprising a Si-based photodetector

Quantum well infrared photodetectors (QWIPs) according to the invention have a surface that provides pseudo-random reflection of the radiation that is incident thereon, resulting in an increase in the effective number of passes of the radiation through the quantum well region, and hence in increased responsivity of the QWIPs, as compared to corresponding prior art grating QWIPs. A convenient approach to forming the pseudo-random reflecting surface is disclosed.

Quantum well photodetector with pseudo-random reflection

Electromagnetic radiation such as, in particular, infrared radiation is detected opto-electronically by means of a superlattice structure forming quantum wells having a single bound state; in the interest of minimizing dark-current, relatively wide barriers are used between quantum wells. Resulting highly sensitive, high-speed detectors can be used in optical communications, for terrain mapping, and for infrared viewing. Furthermore, upon application of a variable electrical potential across the superlattice structure, radiation traversing such structure can be modulated.

Quantum-well radiation-interactive device, and methods of radiation

Radiation-induced effects discovered in layered structures of conductor and semiconductor materials are utilized in radiation-sensitive devices such as, e.g., highly linear as well as highly nonlinear position sensors. Such devices includes a structure of alternating layers of conductor and semiconductor materials, and electrical contacts are provided between which a radiation-induced voltage appears. Among suitable layer materials are silicon and titanium, and resulting devices are sensitive to electromagnetic as well as to particle radiation.

Device including a radiation sensor

A narrow-bandwidth, high-speed infrared radiation detector is based on tunneling of photo-excited electrons out of quantum wells. Infrared radiation incident on a superlattice of doped quantum wells gives rise to intersubband resonance radiation which excites electrons from the ground state into an excited state. A photocurrent results from excited electrons tunneling out of quantum wells. Conveniently, Group III-V materials can be used in device manufacture. Preferably, quantum well potential barriers are shaped so as to facilitate resonant tunneling of photocurrents as compared with dark current. Preferred device operation is at elevated bias voltage, giving rise to enhancement of photocurrent by a quantum-well-avalanche effect.

Infrared-radiation detector device

An avalanche photodetector having separate absorption and multiplication regions comprising Group III-V compound semiconductors is useful as a detector of small numbers of photons when it is operated with an above threshold bias voltage at ambient temperature.

Devices using avalanche photodiode and capable of detecting a small

A photodetector having a graded bandgap region is an ultrahigh speed photodetector when operated at zero bias.

Photodetector with graded bandgap region

Nonlinear devices using 2-methyl-4-nitroaniline are described. Devices using 2-methyl-4-nitroaniline as the active element include second harmonic generators, optical mixers and parametric oscillators which can be operated under phasematched conditions.

2-Methyl-4-nitro-aniline nonlinear optical devices

An optically nonlinear liquid thin film in a thin film optical waveguide is utilized in order to produce optical parametric interactions such as second harmonic generation. Optimization (tuning) of parametric output by 'phase matching' is achieved by means of an electric field which is set up in the liquid film, the field having a spatial periodicity along the propagation direction of the optical waves in the thin film. Alternative or further optimization of parametric output is achieved by varying the thickness of the liquid film in situ.

Growing community of inventors

Livingston, NJ, United States of America

Barry Franklin Levine