Developer of the planar process, the manufacturing process by which modern integrated circuits are built, Hoerni was a silicon transistor pioneer and a member of the Traitorous Eight. Hoerni was born in Geneva, Switzerland, and received a Ph.D. from the University of Cambridge and another Ph.D. from the University of Geneva.
In 1952, he moved to the United States to work at the California Institute of Technology, where he became acquainted with William Shockley, the "father of the transistor." A few years later, Shockley recruited Hoerni to work with him at the newly founded Shockley Semiconductor Laboratory division of Beckman Instruments in Mountain View, California. But Shockley's strange behavior compelled the Traitorous Eight (aka the "Fairchild Eight" and "Shockley's Eight") to abandon him and create the Fairchild Semiconductor corporation. While there, Hoerni went on to invent the planar process, which allowed transistors to be created out of silicon rather than germanium. The name "Silicon Valley" refers to this silicon.
Along with Traitorous Eight alumni Jay Last and Sheldon Roberts, he founded Amelco (known now as Teledyne) in 1961. In 1964, he founded Union Carbide Electronics, and in 1967 Intersil. Hoerni was awarded the Edward Longstreth Medal in 1969 and the McDowell Award in 1972.
An avid mountain climber, he often visited the Karakoram Mountains in Pakistan and was moved by the poverty of the Balti mountain people who lived there. He contributed the lion's share, $12,000, to Greg Mortenson's project to build a school in the remote village of Korphe, and later founded the Central Asia Institute with an endowment of $1 million to continue providing services for them after his death. Hoerni named Greg Mortenson as the first Executive Director of the organization, which continues to build schools in Pakistan and Afghanistan.
In Dec. 2007, an article was published by Michael Riordan about him and his planar process in IEEE Spectrum. The author claimed that Jay Last pointed out that Hoerni had incredible stamina and could hike for hours on little food or water.
