Method for making a ferroelectric device
First Claim
1. A method for forming a semiconductor device, the method comprising the steps of:
- providing a substrate;
forming a plurality of transistors overlying the substrate;
exposing the plurality of transistors to a hydrogen anneal;
forming a barrier layer overlying the plurality of transistors;
forming ferroelectric devices overlying the barrier layer;
exposing the ferroelectric devices to an oxygen anneal; and
wherein the barrier layer prevents the hydrogen anneal from significantly adversely affecting the ferroelectric devices.
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Accused Products
Abstract
A method for forming CMOS transistors and ferroelectric capacitors on a single substrate (10) with improved yield begins by forming CMOS transistors (37a, 37b, 40, 42). A hydrogen anneal using 4-5% hydrogen and a remainder nitrogen is performed to reduce dangling atomic bonds at the gate dielectric/substrate interface of the transistors (37a, 37b, 40, 42). A silicon nitride layer (48) is then deposited over the transistors and on the backside of the wafer substrate (10) in order to substantially encapsulate the effects of the hydrogen anneal to the CMOS transistors (37a, 37b, 40, 42). Ferroelectric capacitor layers (54, 58, 60, 62, 64) are formed overlying the nitride layer (48) where the ferroelectric capacitor layers (54, 58, 60, 62, 64) are oxygen annealed in pure O2. The nitride layer (48) prevents the transistor hydrogen anneal from damaging the ferroelectric material by containing the hydrogen.
125 Citations
28 Claims
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1. A method for forming a semiconductor device, the method comprising the steps of:
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providing a substrate; forming a plurality of transistors overlying the substrate; exposing the plurality of transistors to a hydrogen anneal; forming a barrier layer overlying the plurality of transistors; forming ferroelectric devices overlying the barrier layer; exposing the ferroelectric devices to an oxygen anneal; and wherein the barrier layer prevents the hydrogen anneal from significantly adversely affecting the ferroelectric devices. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A method for forming a semiconductor device, the method comprising the steps of:
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providing a substrate; forming a plurality of CMOS transistors overlying the substrate wherein the plurality of CMOS transistors have a gate-oxide-to-substrate interface; annealing the plurality of CMOS transistors using a hydrogen anneal comprising 3-7% hydrogen and a remainder nitrogen to bind atomic dangling Si bonds at the gate-oxide-to-substrate interface; encapsulating the plurality of CMOS transistors via a silicon nitride barrier layer; and forming ferroelectric capacitors overlying the silicon nitride barrier layer wherein the silicon nitride barrier layer protects the ferroelectric capacitors from adverse affects of the hydrogen anneal. - View Dependent Claims (18, 19, 20, 21)
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22. A method for forming a semiconductor device, the method comprising the steps of:
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providing a substrate; forming a plurality of CMOS transistors overlying the substrate wherein the plurality of CMOS transistors have a gate-oxide-to-substrate interface; annealing the plurality of CMOS transistors via a hydrogen anneal; encapsulating the plurality of CMOS transistors via a silicon nitride barrier layer; forming ferroelectric capacitors overlying the silicon nitride barrier layer wherein the silicon nitride barrier layer protects the ferroelectric capacitors from adverse affects of the hydrogen anneal and; annealing the ferroelectric capacitors in an oxygen ambient within a temperature range of 300°
C. to 500°
C. to improve yield of the ferroelectric capacitors, the silicon nitride barrier layer protecting the plurality of CMOS transistors from adverse affects of the oxygen ambient. - View Dependent Claims (23, 24, 25)
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26. A method for forming a ferroelectric device, the method comprising the steps of:
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forming a ferroelectric capacitor having a first electrode, a second electrode, and a ferroelectric material separating the first electrode and the second electrode; forming a dielectric layer over the ferroelectric capacitor; forming at least one metal contact to one of either the first electrode or the second electrode of the ferroelectric capacitor; and exposing the ferroelectric material to an oxygen anneal to repair the ferroelectric material after the at least one metal contact is formed. - View Dependent Claims (27, 28)
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Specification