Process for treatment of semiconductor
First Claim
1. A process for imparting desirable characteristics to transistor devices of the type having a base region exposed at one surface of said transistor and an emitter region positioned at one side of said base region between an emitter electrode and a non-exposed, masked portion of said base region, said exposed base region being unmasked, and said emitter electrode being of electron ray absorptive material, said process comprising the steps of, irradiating the transistor device with electron rays directed towards said one side of said base region and into said exposed portion of said base region but with said emitter electrode masking said masked portion of said base region, said electron rays being of sufficient energy to produce recombination centers in the unmasked base portion while leaving the masked base portion substantially free of lattice defects, and thereafter heat treating said transistor device.
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Abstract
In the embodiment is specifically described a method for irradiating a transistor device with radiant rays. The top surface of the semiconductor crystal contained in the transistor device is exposed to the radiant rays so that the radiated energy impinging upon a preselected part of the base region, underneath the emitter electrode, is less than that impinging upon the other parts of the base region. Masking and radiant ray absorptive material are used to facilitate the process. Thereafter, the device and/or crystal is subjected to heat treatment to selectively improve such characteristics of the transistor as amplifying and switching characteristics to produce transistors suitable to a necessity of different applications.
15 Citations
9 Claims
- 1. A process for imparting desirable characteristics to transistor devices of the type having a base region exposed at one surface of said transistor and an emitter region positioned at one side of said base region between an emitter electrode and a non-exposed, masked portion of said base region, said exposed base region being unmasked, and said emitter electrode being of electron ray absorptive material, said process comprising the steps of, irradiating the transistor device with electron rays directed towards said one side of said base region and into said exposed portion of said base region but with said emitter electrode masking said masked portion of said base region, said electron rays being of sufficient energy to produce recombination centers in the unmasked base portion while leaving the masked base portion substantially free of lattice defects, and thereafter heat treating said transistor device.
- 3. In a process for treating transistor devices of the type having a base region exposed at one surface of said transistor and an emitter region positioned at one side of said base region between an emitter electrode and a masked portion of said base region, said exposed base region non-exposed being unmasked, and said emitter electrode being of electron ray absorptive material, the steps of, irradiating the transistor device with electron rays directed towards said one side of said base region to produce lattice effects selectively in said exposed portion of said base region and with said emitter electrode preventing the irradiating of said masked portion of said base region, said electron rays being of sufficient energy to produce recombination centers in the unmasked base portion while leaving the masked base portion substantially free of lattice defects, and thereafter heat treating said transistor device at a temperature within the range between the maximum operating temperature of the transistor device and 220°
- 4. A process for imparting desirable characteristics to transistor crystals of the type having a base region exposed at one surface of said transistor and an emitter region positioned at one side of said base region between an emitter electrode and a non-exposed, masked portion of said base region, said exposed base region being unmasked, and said emitter electrode being of electron ray absorptive material, said process comprising the steps of, irradiating a transistor crystal with electron rays directed towards said one side of said base region and into said exposed portion of said base region but with said emitter electrode masking said masked portion of said base region, said electron rays being of sufficient energy to produce recombination centers in the unmasked base portion while leaving the masked base portion substantially free of lattice defects, and heat treating said transistor crystal.
Specification