http://rdf.ncbi.nlm.nih.gov/pubchem/patent/GB-1491435-A
Outgoing Links
| Predicate | Object |
|---|---|
| assignee | http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_b5231c81de1a546c1d6a9325c10910ce |
| classificationCPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/H01L29-864 http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/H01L29-868 |
| classificationIPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/H01L29-868 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/H01L29-864 |
| filingDate | 1976-07-20^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationDate | 1977-11-09^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber | GB-1491435-A |
| titleOfInvention | Negative resistance diode |
| abstract | 1491435 Avalanche transit time diodes RAYTHEON CO 20 July 1976 [13 Aug 1975] 30130/76 Heading H1K An avalanche transit time diode comprises four successive regions i.e. 116; 118; 120; and a region comprising layers 122, 124, 126, of a semiconductive material of varying doping concentrations of the configuration NN<SP>+</SP>NN<SP>++</SP> or PP<SP>+</SP>PP<SP>++</SP>, and a junction-forming material 114, the distance X p , Fig. 2 from the junction to the centre of the second N<SP>+</SP> region 118 being less than 15% of the total distance X p +W x between the said junction and an interface between the third and fourth regions 120, 122 respectively. As shown, Fig. 1, the junctionforming material, typically of gold or chromium forms a Schottky barrier contact with the avalanche layer 116, but a semi-conductor region of a conductivity type different from that of the four regions may alternatively be used. The peak doping concentration in the second region 118 is in the range of 2 x 10<SP>17</SP> to 5 Î 10<SP>17</SP> atoms / cm<SP>3</SP>, and is less than 500 Š thick. The doping concentration in the drift region is between 3 x 10<SP>15</SP> and 3 x 10<SP>16</SP> atoms/cm<SP>3</SP> so that the uniformly decreasing electric field within the region reduces to zero before reaching the interface between the drift region and the first buffer layer. In a method of manufacturing the diode, a highly doped wafer of GaAs is maintained at a temperature of 744‹ C. in a multiple temperature zone furnace tube (446), Fig. 4 (not shown), and vapours of AsCl 3 are carried by dry hydrogen through a dope/etch line (436) and a growth line 434 so as to clean the wafer by etching and simultaneously form GaAs on metallic gallium. During epitaxial deposition of GaAs to form buffer layers 124, 122 and for drift region 120, a mixture of hydrogen and a dopant gas, e.g. H 2 S is continuously introduced in the furnace tube at a rate to produce the preferred doping levels. The doping spike region (118) is shown by propelling quickly the entire contents of a constant volume reservoir (416) by using hydrogen carrier gas, through the dope/etch line, and at the same time continuing the deposition of GaAs. |
| priorityDate | 1975-08-13^^<http://www.w3.org/2001/XMLSchema#date> |
| type | http://data.epo.org/linked-data/def/patent/Publication |
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