tag:blogger.com,1999:blog-7585143205043878857.post2616668808628933728..comments2023-03-15T07:42:58.835-07:00Comments on Analog Footsteps: When Radiation Meant Radio Communications, and then HarrisTodd Nelsonhttp://www.blogger.com/profile/03647633757184486361noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-7585143205043878857.post-25486286958335716212015-04-27T07:24:05.347-07:002015-04-27T07:24:05.347-07:00This comment has been removed by a blog administrator.Anonymoushttps://www.blogger.com/profile/13926222517269876236noreply@blogger.comtag:blogger.com,1999:blog-7585143205043878857.post-57702292987642570092014-10-23T15:40:59.736-07:002014-10-23T15:40:59.736-07:00From a recent email on another topic, Clyde Combs ...From a recent email on another topic, Clyde Combs gave me this description of the development of the dielectric isolation process at Radiation Inc.:<br /><br />A starting wafer of digital starting material, used for digital transistors, was lapped and polished to a thickness of 2 mils. The same was done for an analog slice. Next, we diced up the respective wafers into squares. The squares were then placed on a handle wafer which was oxide coated and<br />put into an epi reactor and over coated with CO2 silicon dioxide which held the squares in place. As the surface was rough, we then again lapped and polished the slice leaving analog and digital islands which were oxide isolated. Note this was originally done to be able to build analog and digital transistors side by side such that the diffusion of dopants for further processing could be contained<br />within the respective island.<br /> <br />This isolation technology was originally fabricated as a diffusion barrier, however we soon found that this would also have important advantages in radiation environments. After the dielectric isolation operation, we used standard wafer/photoresist processing techniques to successfully build analog and digital transistors side by side. In a five year time frame Radiation, Incorporated became the #1 supplier of radiation hardened integrated circuits for strategic market. During this time Radiation, Incorporated was competing against the major semiconductor companies of the time: Texas Instruments,<br />Fairchild, Motorola, and RCA. Starting from this concept stage, there were many days of hard engineering work to make this a cost-effective process for the manufacturing of integrated circuits for military and commercial applications.<br /> <br />After many discussions with other engineers both outside and within our department, I realized the potential of this isolation concept and decided to file a patent on this idea. After consulting with Radiation's lawyers, George Lane and Dub Hudson, I filed a patent request with myself, Ed Guerra, and John Short as inventors. (I added Ed and John to the patent as they were key<br />in helping me to develop the first model.) I then took this application to my boss, Ury Davidon, and he demanded that if I wanted to keep my job at Radiation, he was going to be first on the patent. At that time I decided to let the patent go and not argue the point.<br />Todd Nelsonhttps://www.blogger.com/profile/03647633757184486361noreply@blogger.com