Monitoring negative bias temperature instability (NBTI) and/or positive bias temperature instability (PBTI)
First Claim
1. A ring oscillator circuit for measurement of at least one of negative bias temperature instability effect and positive bias temperature instability effect, said circuit comprising:
- a ring oscillator comprising first and second rails, and an odd number of repeating circuit structures, said odd number being at least three, each of said repeating circuit structures comprising;
an input terminal and an output terminal;
a first p-type transistor having a gate, a first drain-source terminal coupled to said first rail, and a second drain source terminal selectively coupled to said output terminal;
a first n-type transistor having a gate, a first drain-source terminal coupled to said second rail, and a second drain source terminal selectively coupled to said output terminal; and
repeating-circuit-structure control circuitry;
wherein each of said repeating circuit structures has its output terminal connected to said input terminal of an immediately adjacent one of said repeating circuit structures; and
a voltage supply and control block coupled to said ring oscillator and configured to cooperate with said repeating-circuit-structure control circuitry such that;
during a negative bias temperature instability effect direct current stress mode, said gates of said first n-type transistors are grounded to turn them off, a stress voltage differential is applied between said first rail and said gates of said first p-type transistors to stress them, and said second rail is grounded;
during a positive bias temperature instability effect direct current stress mode, said gates of said first p-type transistors are held at a nominal supply voltage to turn them off, a stress voltage differential is applied between said second rail and said gates of said first n-type transistors to stress them, and said first rail is held at said nominal supply voltage; and
during a measurement mode, said nominal supply voltage is applied to said first rail and a ground to said second rail, and said second drain source terminals of said first n-type transistors and said first p-type transistors are coupled to said output terminals, such that each of said repeating circuit structures functions as an inverter.
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Accused Products
Abstract
A ring oscillator circuit for measurement of negative bias temperature instability effect and/or positive bias temperature instability effect includes a ring oscillator having first and second rails, and an odd number (at least 3) of repeating circuit structures. Each of the repeating circuit structures in turn includes an input terminal and an output terminal; a first p-type transistor having a gate, a first drain-source terminal coupled to the first rail, and a second drain source terminal selectively coupled to the output terminal; a first n-type transistor having a gate, a first drain-source terminal coupled to the second rail, and a second drain source terminal selectively coupled to the output terminal; and repeating-circuit-structure control circuitry. The ring oscillator circuit also includes a voltage supply and control block.
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Citations
16 Claims
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1. A ring oscillator circuit for measurement of at least one of negative bias temperature instability effect and positive bias temperature instability effect, said circuit comprising:
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a ring oscillator comprising first and second rails, and an odd number of repeating circuit structures, said odd number being at least three, each of said repeating circuit structures comprising; an input terminal and an output terminal; a first p-type transistor having a gate, a first drain-source terminal coupled to said first rail, and a second drain source terminal selectively coupled to said output terminal; a first n-type transistor having a gate, a first drain-source terminal coupled to said second rail, and a second drain source terminal selectively coupled to said output terminal; and repeating-circuit-structure control circuitry; wherein each of said repeating circuit structures has its output terminal connected to said input terminal of an immediately adjacent one of said repeating circuit structures; and a voltage supply and control block coupled to said ring oscillator and configured to cooperate with said repeating-circuit-structure control circuitry such that; during a negative bias temperature instability effect direct current stress mode, said gates of said first n-type transistors are grounded to turn them off, a stress voltage differential is applied between said first rail and said gates of said first p-type transistors to stress them, and said second rail is grounded; during a positive bias temperature instability effect direct current stress mode, said gates of said first p-type transistors are held at a nominal supply voltage to turn them off, a stress voltage differential is applied between said second rail and said gates of said first n-type transistors to stress them, and said first rail is held at said nominal supply voltage; and during a measurement mode, said nominal supply voltage is applied to said first rail and a ground to said second rail, and said second drain source terminals of said first n-type transistors and said first p-type transistors are coupled to said output terminals, such that each of said repeating circuit structures functions as an inverter. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method comprising the steps of:
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providing a ring oscillator comprising first and second rails, and an odd number of repeating circuit structures, said odd number being at least three, each of said repeating circuit structures comprising; an input terminal and an output terminal; a first p-type transistor having a gate, a first drain-source terminal coupled to said first rail, and a second drain source terminal selectively coupled to said output terminal; and a first n-type transistor having a gate, a first drain-source terminal coupled to said second rail, and a second drain source terminal selectively coupled to said output terminal; wherein each of said repeating circuit structures has its output terminal connected to said input terminal of an immediately adjacent one of said repeating circuit structures; during a negative bias temperature instability effect direct current stress mode, grounding said gates of said first n-type transistors to turn them off, applying a stress voltage differential between said first rail and said gates of said first p-type transistors to stress them, and grounding said second rail; during a positive bias temperature instability effect direct current stress mode, holding said gates of said first p-type transistors at a nominal supply voltage to turn them off, applying a stress voltage differential between said second rail and said gates of said first n-type transistors to stress them, and holding said first rail at said nominal supply voltage; and during a measurement mode, applying said nominal supply voltage to said first rail and a ground to said second rail, and coupling said second drain source terminals of said first n-type transistors and said first p-type transistors to said output terminals, such that each of said repeating circuit structures functions as an inverter. - View Dependent Claims (8, 9, 10, 11)
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12. A design structure tangibly embodied in a machine readable medium for designing, manufacturing, or testing an integrated circuit, said design structure comprising a ring oscillator circuit for measurement of at least one of negative bias temperature instability effect and positive bias temperature instability effect, said circuit comprising:
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a ring oscillator comprising first and second rails, and an odd number of repeating circuit structures, said odd number being at least three, each of said repeating circuit structures comprising; an input terminal and an output terminal; a first p-type transistor having a gate, a first drain-source terminal coupled to said first rail, and a second drain source terminal selectively coupled to said output terminal; a first n-type transistor having a gate, a first drain-source terminal coupled to said second rail, and a second drain source terminal selectively coupled to said output terminal; and repeating-circuit-structure control circuitry; wherein each of said repeating circuit structures has its output terminal connected to said input terminal of an immediately adjacent one of said repeating circuit structures; and a voltage supply and control block coupled to said ring oscillator and configured to cooperate with said repeating-circuit-structure control circuitry such that; during a negative bias temperature instability effect direct current stress mode, said gates of said first n-type transistors are grounded to turn them off, a stress voltage differential is applied between said first rail and said gates of said first p-type transistors to stress them, and said second rail is grounded; during a positive bias temperature instability effect direct current stress mode, said gates of said first p-type transistors are held at a nominal supply voltage to turn them off, a stress voltage differential is applied between said second rail and said gates of said first n-type transistors to stress them, and said first rail is held at said nominal supply voltage; and during a measurement mode, said nominal supply voltage is applied to said first rail and a ground to said second rail, and said second drain source terminals of said first n-type transistors and said first p-type transistors are coupled to said output terminals, such that each of said repeating circuit structures functions as an inverter. - View Dependent Claims (13, 14, 15, 16)
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Specification