Editing Diode (section)

===Point-contact diodes===
Point-contact diodes were developed starting in the 1930s, out of the early [[crystal detector]] technology, and are now generally used in the 3 to 30 gigahertz range.<ref name="Scaff_Ohl_01"/><ref name="SG">{{cite web| url = https://www.semigen.net/point-contact-diodes/| title = SemiGen Inc.}}</ref><ref name="AS">{{cite web| url = http://www.advancedsemiconductor.com/pdf/diodes/SiliconPointContactMixer.pdf| title = Advanced Semiconductor, Inc.| access-date = 2018-05-24| archive-date = 2023-05-21| archive-url = https://web.archive.org/web/20230521233514/http://www.advancedsemiconductor.com/pdf/diodes/SiliconPointContactMixer.pdf| url-status = dead}}</ref><ref name="MB">{{cite web| url = https://massbaytech.com/point-contact-diodes/| title = Massachusetts Bay Technologies}}</ref> Point-contact diodes use a small diameter metal wire in contact with a semiconductor crystal, and are of either ''non-welded'' contact type or ''welded contact'' type. Non-welded contact construction utilizes the Schottky barrier principle. The metal side is the pointed end of a small diameter wire that is in contact with the semiconductor crystal.<ref name="HC">{{cite web| url = https://www.scribd.com/document/37134001/MIT-Radiaton-Lab-Series-V15-Crystal-Rectifiers| title = H. C. Torrey, C. A. Whitmer, ''Crystal Rectifiers'', New York: McGraw-Hill, 1948}}</ref> In the welded contact type, a small P region is formed in the otherwise N-type crystal around the metal point during manufacture by momentarily passing a relatively large current through the device.<ref>{{cite web| url = https://patentimages.storage.googleapis.com/fe/87/8a/7e1064ddfc7d8a/US2704818.pdf| title = H. Q. North, ''Asymmetrically Conductive Device'', U.S. patent 2,704,818}}</ref><ref>{{cite web| url = https://archive.org/stream/neetsmodules_202003/NEETS%20MOD%2011%20NAVEDTRA%2014183A#page/n181/mode/2up| title = U. S. Navy Center for Surface Combat Systems, ''Navy Electricity and Electronics Training Series, Module 11'', 2012, pp. 2-81–2-83}}</ref> Point contact diodes generally exhibit lower capacitance, higher forward resistance and greater reverse leakage than junction diodes.