# US 2014/0154848 A1 · N/P METAL CRYSTAL ORIENTATION FOR HIGH-K METAL GATE Vt MODULATION

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- Number: US 2014/0154848 A1
- Document ID: US20140154848A1
- Status: Published application
- Kind: A1
- Application number: 14/174,689
- Filed: 2014-02-06
- Published: 2014-06-05
- Earliest claimed: 2008-12-10
- Assignees: Taiwan Semiconductor Manufacturing Company, Ltd.
- Applicants: Taiwan Semiconductor Manufacturing Company, Ltd.
- Inventors: Su-Horng Lin; Chi-Ming Yang; Chyi Shyuan Chern; Chin-Hsiang Lin
- Web page: https://patentgrep.com/patent/US20140154848A1

## CPC

- H10D 84/038: {using silicon technology, e.g. SiGe}
- H10D 64/01316: {the conductor comprising a layer of elemental metal contacting the insulator, e.g. Ta, W, Mo or Al}
- H10D 64/666: {the conductor further comprising additional layers}
- H10D 84/0177: {the gate conductors having different materials or different implants}
- H10D 84/0181: {Manufacturing their gate insulating layers}
- H10D 84/856: {the complementary IGFETs having different architectures than each other, e.g. high-voltage and low-voltage CMOS}
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES

## Abstract

The present disclosure provides an integrated circuit. The integrated circuit includes a semiconductor substrate having a first region and a second region; a first gate stack of an n-type field-effect transistor (FET) in the first region; and a second gate stack of a p-type FET in the second region. The first gate stack includes a high k dielectric layer on the semiconductor substrate, a first crystalline metal layer in a first orientation on the high k dielectric layer, and a conductive material layer on the first crystalline metal layer. The second gate stack includes the high k dielectric layer on the semiconductor substrate, a second crystalline metal layer in a second orientation on the high k dielectric layer, and the conductive material layer on the second crystalline metal layer.

## Claims

### Claim 1

A method for fabricating a semiconductor device comprising:
providing a semiconductor substrate having a first region and a second region;
forming a high k dielectric layer on a semiconductor substrate;
forming a first crystalline metal feature with a first orientation on the high k dielectric layer in the first region, wherein the first orientation is {100};
forming a second crystalline metal feature with a second orientation on the high k dielectric layer in the second region, wherein the second orientation is {111};
forming a first source and first drain in the semiconductor substrate in the first region, wherein the first source and first drain include n-type dopant and wherein the first crystalline metal feature is interposed between the first source and first drain; and
forming a second source and second drain in the semiconductor substrate in the second region, wherein the second source and second drain include p-type dopant and wherein the second crystalline metal feature is interposed between the second source and second drain.

### Claim 2 (depends on 1)

The method of claim 1, wherein the first crystalline metal feature includes tantalum (Ta) formed by a physical vapor deposition (PVD) process using a power ranging between about 100 W and about 1000 W, a pressure of about 2×10−4 torr, and an argon gas flow ranging between about 3 sccm and about 50 sccm.

### Claim 3 (depends on 1)

The method of claim 1, wherein the second crystalline metal feature includes platinum (Pt) formed by an e-gun evaporation process using a deposition temperature ranging between about 300 C and about 700 C.

### Claim 4 (depends on 1)

The method of claim 1, wherein the first crystalline metal feature and second crystalline metal feature each includes ruthenium (Ru).

### Claim 5 (depends on 4)

The method of claim 4, wherein the first crystalline metal feature is formed by one of:
by PVD at about 300 C;
by MOCVD at a deposition temperature exceeding about 400 C; and
by PVD with Ar+ energy of about 500 eV and incident angle of about 75°, and the current density greater than 1.2 A/m2.

### Claim 6 (depends on 4)

The method of claim 4, wherein the second crystalline metal feature is formed by MOCVD at a deposition temperature not exceeding about 300 C.

### Claim 7

A method for fabricating an integrated circuit, comprising:
providing a semiconductor substrate having a first region and a second region;
forming, in the first region, an n-type field-effect transistor (FET) having a first gate stack, wherein the forming includes:
forming first gate spacers disposed on opposing sidewalls of the first gate stack;
forming a high k dielectric layer disposed over the semiconductor substrate;
forming a tantalum layer disposed over the high k dielectric layer, wherein the tantalum layer has a {100} orientation interfacing the high k dielectric layer; and
forming a first conductive metal material layer disposed over and in physical contact with the tantalum layer, wherein all portions of the first conductive metal material layer are disposed between the first gate spacers; and
forming, in the second region, a p-type FET having a second gate stack, wherein the forming includes:
forming second gate spacers disposed on opposing sidewalls of the second gate stack;
forming the high k dielectric layer over the semiconductor substrate;
forming a platinum layer disposed over the high k dielectric material layer, wherein the platinum layer has a {111} orientation interfacing the high k dielectric layer; and
forming a second conductive metal material layer disposed over and in physical contact with the platinum layer, wherein all portions of the second conductive metal material layer are disposed between the second gate spacers.

### Claim 8 (depends on 7)

The method of claim 7, wherein the high k dielectric layer includes hafnium oxide.

### Claim 9 (depends on 7)

The method of claim 7, wherein forming the tantalum layer includes utilizing a physical vapor deposition (PVD) process with a power ranging between about 100 W and about 1000 W, a pressure of about 2×10−4 torr, and an argon gas flow ranging between about 3 sccm and about 50 sccm.

### Claim 10 (depends on 7)

The method of claim 7, wherein forming the platinum layer includes utilizing an e-gun evaporation process with a deposition temperature ranging between about 300 C and about 700 C.

### Claim 11 (depends on 7)

The method claim 7, wherein the first conductive metal material layer includes one of copper, aluminum, and tungsten.

### Claim 12 (depends on 7)

The method of claim 7, wherein the first conductive metal material layer is free of silicide.

### Claim 13

A method for fabricating an integrated circuit, comprising:
providing a semiconductor substrate having a first region and a second region, the second region being adjacent to the first region;
forming, in the first region, an n-type field-effect transistor (FET) having a first gate electrode, wherein the forming includes:
forming a first channel region defined between a first source region and a first drain region;
forming a first crystalline metal layer disposed over and in physical contact with a high k dielectric layer, the first crystalline metal layer having a {100} orientation; and
forming a first conductive metal material layer disposed over and in physical contact with the first crystalline metal layer, the first conductive metal material layer being further disposed directly over the first channel region; and
forming a p-type FET in the second region having a second gate electrode, wherein the forming includes:
forming a second channel region defined between a second source region and a second drain region;
forming a second crystalline metal layer disposed over and in physical contact with the high k dielectric material layer, the second crystalline metal layer having a {111} orientation and being formed of a different metal than the first crystalline metal layer; and
forming a second conductive metal material layer disposed over and in physical contact with the second crystalline metal layer, the second conductive metal material layer being further disposed directly over the second channel region.

### Claim 14 (depends on 13)

The method of claim 13, wherein the semiconductor substrate includes silicon.

### Claim 15 (depends on 13)

The method of claim 13, the first crystalline metal layer includes tantalum (Ta).

### Claim 16 (depends on 13)

The method of claim 13, wherein forming the first crystalline metal layer includes utilizing a physical vapor deposition (PVD) with a power ranging between about 100 W and about 1000 W, a pressure of about 2×10−4 torr, and an argon gas flow ranging between about 3 and 50 sccm.

### Claim 17 (depends on 13)

The method of claim 13, wherein the second crystalline metal layer includes platinum (Pt).

### Claim 18 (depends on 13)

The method of claim 13, wherein forming the second crystalline metal layer includes utilizing e-gun evaporation with a temperature ranging between about 300 C and about 700 C.

### Claim 19 (depends on 13)

The method of claim 13, wherein the first and second crystalline metal layers each include a different one of lanthanum (La), hafnium (Hf), ruthenium (Ru), zirconium (Zr), titanium (Ti), tantalum (Ta), tungsten (W), nickel (Ni) and platinum (Pt).

### Claim 20 (depends on 13)

The method of claim 13, wherein the first crystalline metal layer includes PtTiO.