# US 2021/0280720 A1 · Ferroelectric thin-film structure and electronic device including the same

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- Number: US 2021/0280720 A1
- Document ID: US20210280720A1
- Status: Published application
- Kind: A1
- Application number: 17/112,355
- Filed: 2020-12-04
- Published: 2021-09-09
- Earliest claimed: 2020-03-03
- Assignees: Samsung Electronics Co., Ltd.
- Applicants: Samsung Electronics Co., Ltd.
- Inventors: Yunseong Lee; Jinseong Heo; Sangwook Kim; Taehwan Moon; Sanghyun Jo
- Web page: https://patentgrep.com/patent/US20210280720A1

## CPC

- H10B 51/40: characterised by the peripheral circuit region
- H10D 30/701: {IGFETs having ferroelectric gate insulators, e.g. ferroelectric FETs}
- H10B 51/30: characterised by the memory core region
- H10D 64/689: {having ferroelectric layers}
- H10P 14/69392: {the material containing hafnium, e.g. HfO2}
- H10P 14/69395: {the material containing zirconium, e.g. ZrO2}
- H10B: ELECTRONIC MEMORY DEVICES
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10

## Abstract

Provided is a ferroelectric thin-film structure including a semiconductor substrate, a first ferroelectric layer on the semiconductor substrate, and a second ferroelectric layer on the semiconductor substrate. The second ferroelectric layer is spaced apart from the first ferroelectric layer and has a different dielectric constant from the first ferroelectric layer. The first ferroelectric layer and the second ferroelectric layer may be different from each other in terms of the amount of a dopant contained therein, and may exhibit different threshold voltages when applied to transistors.

## Claims

### Claim 1

A ferroelectric thin-film structure comprising:
a semiconductor substrate;
a first ferroelectric layer on the semiconductor substrate; and
a second ferroelectric layer on the semiconductor substrate, the second ferroelectric layer spaced apart from the first ferroelectric layer, a dielectric constant of the second ferroelectric layer being different than a dielectric constant of the first ferroelectric layer.

### Claim 2 (depends on 1)

The ferroelectric thin-film structure of claim 1, wherein the first ferroelectric layer and the second ferroelectric layer comprise a HfO2-based dielectric material.

### Claim 3 (depends on 2)

The ferroelectric thin-film structure of claim 2, wherein
the first ferroelectric layer comprises HfxZr(1-x)O, wherein 0<x<1, and
the second ferroelectric layer comprises HfxZr(1-x)O doped with a dopant, wherein 0<x<1.

### Claim 4 (depends on 3)

The ferroelectric thin-film structure of claim 3, wherein the dopant comprises one of Si, Hf, Zr, Al, La, Y, Sr, and Gd.

### Claim 5 (depends on 3)

The ferroelectric thin-film structure of claim 3, wherein the first ferroelectric layer comprises:
at least one first atomic layer including HfO2; and
at least one second atomic layer including ZrO2.

### Claim 6 (depends on 3)

The ferroelectric thin-film structure of claim 3, wherein the second ferroelectric layer comprises:
at least one first atomic layer including HfO2;
at least one second atomic layer including ZrO2; and
at least one third atomic layer including HfO2 doped with the dopant or ZrO2 doped with the dopant.

### Claim 7 (depends on 6)

The ferroelectric thin-film structure of claim 6, wherein the at least one third atomic layer has a thickness of about 10 nm or less.

### Claim 8 (depends on 3)

The ferroelectric thin-film structure of claim 3, wherein an amount of the dopant is in a range of about 1% to about 10%.

### Claim 9

An electronic device comprising:
a semiconductor substrate including a first channel region, a first source and a first drain each connected to the first channel region, a second channel region, and a second source and a second drain each connected to the second channel region;
a first transistor including the first channel region, the first source, the first drain, a first ferroelectric layer on the first channel region, and a first gate electrode on the first ferroelectric layer; and
a second transistor including the second channel region, the second source, the second drain, a second ferroelectric layer on the second channel region, and a second gate electrode on the second ferroelectric layer, a dielectric constant of the second ferroelectric layer being different than a dielectric constant of the first ferroelectric layer.

### Claim 10 (depends on 9)

The electronic device of claim 9, wherein the first ferroelectric layer and the second ferroelectric layer comprise a HfO2-based dielectric material.

### Claim 11 (depends on 10)

The electronic device of claim 10, wherein
the first ferroelectric layer comprises HfxZr(1-x)O, wherein 0<x<1, and
the second ferroelectric layer comprises HfxZr(1-x)O doped with a dopant, wherein 0<x<1.

### Claim 12 (depends on 11)

The electronic device of claim 11, wherein the dopant comprises one of Si, Al, La, Y, Sr, and Gd.

### Claim 13 (depends on 11)

The electronic device of claim 11, wherein the first ferroelectric layer comprises:
at least one first atomic layer including HfO2; and
at least one second atomic layer including ZrO2.

### Claim 14 (depends on 11)

The electronic device of claim 11, wherein the second ferroelectric layer comprises:
at least one first atomic layer including HfO2;
at least one second atomic layer including ZrO2; and
at least one third atomic layer including HfO2 doped with the dopant or ZrO2 doped with the dopant.

### Claim 15 (depends on 14)

The electronic device of claim 14, wherein the at least one third atomic layer is located at a position closest to the second channel region among the at least one first atomic layer, the at least one second atomic layer, and the at least one third atomic layer.

### Claim 16 (depends on 14)

The electronic device of claim 14, wherein the at least one third atomic layer has a thickness of about 10 nm or less.

### Claim 17 (depends on 11)

The electronic device of claim 11, wherein an amount of the dopant is in a range of about 1% to about 10%.

### Claim 18 (depends on 9)

The electronic device of claim 9, wherein the first channel region and the second channel region each comprise at least one of Si, Ge, SiGe, a Group III-V semiconductor, an oxide semiconductor, a nitride semiconductor, an oxynitride semiconductor, a two-dimensional (2D) material, quantum dots, and an organic semiconductor.

### Claim 19 (depends on 9)

The electronic device of claim 9, wherein at least one of the first transistor and the second transistor further comprises an insulating layer between the first channel region and the first ferroelectric layer or between the second channel region and the second ferroelectric layer.

### Claim 20 (depends on 9)

The electronic device of claim 9, wherein at least one of the first transistor and the second transistor further comprises:
an insulating layer between the first ferroelectric layer and the first gate electrode or between the second ferroelectric layer and the second gate electrode; and
a metal layer between the insulating layer and the first ferroelectric layer or between the insulating layer and the second ferroelectric layer.

### Claim 21 (depends on 9)

The electronic device of claim 9, wherein one of the first transistor and the second transistor is a transistor for a logic device and an other of the first transistor and the second transistor is a transistor for a memory device.

### Claim 22

A ferroelectric thin-film structure comprising:
a semiconductor substrate; and
a first ferroelectric layer and a second ferroelectric layer spaced apart from each other on the semiconductor substrate,
the first ferroelectric layer and the second ferroelectric layer each including a plurality of first atomic layers and a plurality of second atomic layers stacked on each other,
a material of the plurality of first atomic layers being different than a material of the plurality of second atomic layers, and
the second ferroelectric layer further including one or more third atomic layers having a dopant.

### Claim 23 (depends on 22)

The ferroelectric thin-film structure of claim 22, wherein
the plurality of first atomic layers include HfO2,
the plurality of second atomic layers include ZrO2, and
the one or more third atomic layers include HfO2 or ZrO2.

### Claim 24 (depends on 22)

The ferroelectric thin-film structure of claim 22, wherein
the dopant includes one of Si, Hf, Zr, Al, La, Y, Sr, and Gd.

### Claim 25 (depends on 22)

The ferroelectric thin-film structure of claim 22, wherein
the one or more third atomic layers each have a thickness of about 10 nm or less.

### Claim 26 (depends on 22)

An electronic device, comprising:
the ferroelectric thin-film structure of claim 22;
a first transistor including the first ferroelectric layer; and
a second transistor including the second ferroelectric layer, wherein
a threshold voltage of the first transistor is different than a threshold voltage of the second transistor.