摘要:
Disclosed herein is a process for growing II-IV semiconductor crystals which includes providing both a II-IV semiconductor source material and a crystal growth support member in a predetermined dynamic vacuum. This vacuum is sufficient to create a predetermined overpressure at the source material and simultaneously remove impurities therefrom. The temperature of the support member is initally raised to a predetermined level above the temperature of the source material to thereby prevent vapor transport between the two. Then, the temperature of the support member is lowered to a predetermined value below that of the source material to produce a disassociation of elemental gases from the source material and initiate controlled vapor transport of the elemental gases from the source material to the support member. In this manner, compound semiconductor crystals of high purity and stoichiometry are formed on the surface of the support member.
摘要:
The specification describes a process for growing selected compound semiconductors of high stoichiometry and purity and includes the steps of providing both a dynamic vacuum and a predetermined temperature profile in a container or tube containing a chosen semiconductor source material. The dynamic vacuum is used to create a predetermined minimum overpressure. P.sub.min, in this container with respect to the vapor pressure of the source material, while simultaneously removing impurities through in opening in the container during the crystal growth process. This process involves the vapor transport of elements of the selected compound semiconductor from the source material to a suitable support member, such as a graphite crucible which is maintained at a predetermined uniform controlled temperature. Alternatively, the crystal growth process can be in the form of a vapor phase epitaxial process wherein the selected compound semiconductor is epitaxially deposited on a chosen semiconductor substrate whose temperature is also closely controlled.
摘要:
A carrier is described that adapts an excavator with an dozer blade to a tote bucket or scoop. The excavator carrier rests on the blade at its bottom with the blade serving as the back of the carrier. Dumping capability is provided by pivoting the carrier on mounting pins between a mounting bracket added to the back of the blade at its top and a corresponding mounting bracket on the carrier. A backhoe on the excavator can be used to lift the front of the carrier causing the carrier to pivot on the mounting pin and dump material through the separation of the the carrier and the blade at its bottom. Side plates of the carrier extend beyond the back of the blade in a shearing action to maintain self alignment. Quick separation of the carrier from the excavator blade is obtained by simply removing mounting pins on which the carrier pivots and using the backhoe to move the carrier conversion away from the excavator or backing the excavator away from the carrier.
摘要:
A device for controlling fluid flow for heating or cooling an associated system is provided. The present invention includes a housing having a flow control member that includes a bendable portion. The flow control member responds automatically to a pressure condition within the housing and opens or closes based on the direction and quantity of fluid flow and does not include any mechanical or electromechanical control components. The bendable portion may include, for example, a convoluted section. The flow control member is in an open position during a mode of operation of the associated system and is in a closed position in another mode of operation of the system.