Browse Prior Art Database

Process for Making MOSFET's

IP.com Disclosure Number: IPCOM000074339D
Original Publication Date: 1971-Apr-01
Included in the Prior Art Database: 2005-Feb-23
Document File: 2 page(s) / 28K

Publishing Venue

IBM

Related People

Fowler, AB: AUTHOR [+2]

Abstract

Selected regions 8 and 10 of a p-type silicon wafer 2 are doped by any known means to make them heavily n-type so that such regions 8 and 10 are the source and drain regions, respectively, of the ultimate MOSFET device. A thin layer of silicon dioxide 6 isolates a gate member 12 of molybdenum from regions 8 and 10. Implantation of phosphorus ions takes place, the ion implantation extending the source region 8 to include region 14 and the drain region 10 to include region 16 so as to achieve accurate location of the source and drain regions with respect to the gate. The incomplete device is annealed to temperatures > 600 degrees C, after which photoresist 18 is deposited over regions 12, 14 and 16. Aluminum 20 is then deposited over the entire surface as shown in A.

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Process for Making MOSFET's

Selected regions 8 and 10 of a p-type silicon wafer 2 are doped by any known means to make them heavily n-type so that such regions 8 and 10 are the source and drain regions, respectively, of the ultimate MOSFET device. A thin layer of silicon dioxide 6 isolates a gate member 12 of molybdenum from regions 8 and 10. Implantation of phosphorus ions takes place, the ion implantation extending the source region 8 to include region 14 and the drain region 10 to include region 16 so as to achieve accurate location of the source and drain regions with respect to the gate. The incomplete device is annealed to temperatures > 600 degrees C, after which photoresist 18 is deposited over regions 12, 14 and 16. Aluminum 20 is then deposited over the entire surface as shown in A. The subsequent removal of the photoresist 18 causes the aluminum 20 over it to break away, leaving the finished structure shown in B. This method allows the aluminum to be put down after high temperature annealing.

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