Semiconductor device and manufacturing method of the same
First Claim
1. A semiconductor device, comprising:
- an internal transistor constructing an internal circuit; and
a protection transistor which protects said internal transistor from breakage due to static electricity occurring between power supply pads, a conductivity type of a channel of said protection transistor corresponding to a conductivity type of said internal transistor, and drain junction of said protection transistor being sharper than drain junction of said internal transistor.
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Accused Products
Abstract
A protection transistor which protects an internal transistor in an internal circuit from breakage due to static electricity occurring between power supply pads is provided. A conductivity type of a first p-well constructing a channel of the protection transistor corresponds to a conductivity type of a second p-well constructing a channel of the internal transistor. An impurity concentration of the first p-well is higher than an impurity concentration of the second p-well. Accordingly, drain junction of the protection transistor is sharper than drain junction of the internal transistor, and starting voltage of a parasitic bipolar operation of the protection transistor is lower than that of the internal transistor. Therefore, the internal circuit can be properly protected from an ESD surge.
22 Citations
20 Claims
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1. A semiconductor device, comprising:
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an internal transistor constructing an internal circuit; and
a protection transistor which protects said internal transistor from breakage due to static electricity occurring between power supply pads, a conductivity type of a channel of said protection transistor corresponding to a conductivity type of said internal transistor, and drain junction of said protection transistor being sharper than drain junction of said internal transistor. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A manufacturing method of a semiconductor device, comprising the step of:
forming an internal transistor constructing an internal circuit, and a protection transistor which protects the internal transistor from breakage due to static electricity occurring between electric power pads, a conductivity type of a channel of the protection transistor being made to correspond to a conductivity type of the internal transistor, and drain junction of the protection transistor being made sharper than drain junction of the internal transistor. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
Specification