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US 4,044,452 AGranted
Process for making field effect and bipolar transistors on the same semiconductor chip
AssigneeInternational Business Machines Corporation
InventorsShakir Ahmed Abbas, Robert Charles Dockerty
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Abstract
A process and the resulting structure for making metal oxide silicon field effect transistors and vertical bipolar transistors on the same semiconductor chip with the devices being dielectrically isolated from each other. The process does not require an epitaxial layer. The bipolar devices have utility as cross-chip or off-chip drivers or can be utilized for analog circuitry.
Claims7
Method for manufacturing an integrated circuit structure having dielectrically isolated regions containing bipolar and field effect transistor devices comprising:
- providing a silicon monocrystalline substrate;
- etching said silicon in the areas to be the dielectric regions isolating the said field effect transistor devices;
- oxidizing the exposed silicon in said regions to form first oxidized areas;
- etching said silicon in the areas to be the dielectric regions isolating the said bipolar devices to form a mesa in the center of the etched area;
- oxidizing the exposed silicon areas to form a screen oxide area;
- ion implanting impurities through said screen oxide areas to form the subcollector for a bipolar device;
- growing thick silicon dioxide in said screen oxide areas to completely fill the areas with silicon dioxide and complete said dielectrically isolated regions;
- simultaneously forming the source, drain and emitter regions of said devices;
- forming gate insulator and gate electrodes for said field effect transistor devices;
- forming electrical contacts to said source, drain, gate, emitter, base and, collector of said devices.
7 more elements
Dependencies are inferred from the claim text.