METHOD FOR FORMING A DIELECTRIC LAYER

• US 20080176375A1
• Filed: 01/08/2008
• Published: 07/24/2008
• Est. Priority Date: 01/19/2007
• Status: Abandoned Application

• Current Assignee: Qimonda AG (Infineon Technologies AG)
• Original Assignee: Qimonda AG (Infineon Technologies AG)
• Inventors: Kudelka, Stephan, Erben, Elke, Kersch, Alfred, Patz, Matthias, Sundqvist, Jonas, Link, Angela
• Application Number:
  US11/970,654
• Publication Number:
  US 20080176375A1
• Time in Patent Office: Days
• US Class Current: 438/386
• CPC Class Codes: C23C 16/0272 Deposition of sub-layers, e.g. to promote the adhesion of the main coating
• CPC Class Codes: C23C 16/405 of refractory metals or yttrium
• CPC Class Codes: C23C 16/45553 characterized by the use of precursors specially adapted for ALD
• CPC Class Codes: H01L 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD
• CPC Class Codes: H01L 21/3141 Deposition using atomic layer deposition techniques [ALD]
• CPC Class Codes: H01L 21/31641 Deposition of Zirconium oxides, e.g. ZrO2
• CPC Class Codes: H01L 21/31645 Deposition of Hafnium oxides, e.g. HfO2
• CPC Class Codes: H01L 28/40 Capacitors

Abstract

The present invention relates to a deposition of a dielectric layer. On a substrate having a structured area a crystallization seed layer for a dielectric layer is deposited via an atomic layer deposition technique employing a first and a second precursor on the structured area of the substrate. The first pre-cursor is a compound having the constitutional formula M¹(R¹Cp)_x(R²)_4-x, wherein M¹ is one of hafnium and zirconium, Cp is cyclopentadienyl, R¹ is independently selected of methyl, ethyl and alkyl, R² is independently selected of hydrogen, methyl, ethyl, alkyl and alkoxyl, and x is one or two. The dielectric layer is deposited on the crystallization seed layer via an atomic layer deposition technique employing a third and a forth precursor wherein the third pre-cursor being a compound having the constitutional formula M² R³ R⁴ R⁵ R⁶, wherein M² is one of hafnium or zirconium and R³, R⁴, R⁵, and R⁶ are independently selected of alkyl amines.

Claims

1. A method for forming a dielectric layer, comprising the steps:

providing a substrate having a structured area,

depositing a crystallization seed layer for a dielectric layer via an atomic layer deposition technique employing a first and a second precursor on the structured area of the substrate, the first pre-cursor being a compound having the constitutional formula M¹(R¹Cp)_x(R²)_4-x, wherein

M¹ is one of hafnium and zirconium,

Cp is cyclopentadienyl,

R¹ is independently selected of methyl, ethyl and alkyl,

R² is independently selected of hydrogen, methyl, ethyl, alkyl, alkoxyl, and halogen, and

x is one or two, and;

depositing the dielectric layer on the crystallization seed layer via an atomic layer deposition technique employing a third and a forth precursor wherein the third precursor being a compound having the constitutional formula M² R³ R⁴ R⁵ R⁶, wherein

M² is one of hafnium or zirconium and

R³, R⁴, R⁵, and R⁶ are independently selected of alkyl amines.

2. The method according to claim 1, wherein the crystallization seed layer is deposited at a temperature in the range of 300°

to 500°

C.

3. The method according to claim 2, wherein the alkyl amine is one of the group of methyl amine and ethyl amine.

4. The method according to claim 1, wherein a dopant material is applied to the dielectric layer during reacting the first pre-cursor and the second pre-cursor, the dopant material consisting of the group of silicon, aluminium, rare earth metal, titanium, hafnium, tantalum, strontium, barium, scandium, yttrium, lanthanum, niobium, bismuth, calcium and cerium.

5. The method according to claim 4, wherein the concentration of the dopant material in the dielectric layer is in the range of 1-20 atomic percent relative to the transition metal.

6. The method according to claim 1, wherein a fifth precursor is used additional to the third precursor, the fifth precursor is selected of at least one of the formula of Al(CH₃)₃, Si(NR¹₂)₄, SiH(NR¹₂)₃, SiH₂(NR¹₂)₂, wherein R¹ is independently selected from methyl and ethyl

7. A method for forming a capacitor, comprising the steps:

providing a substrate having a structured area;

forming a trench in the substrate;

forming a first electrode in or on the trench side walls;

depositing a crystallization seed layer for a dielectric layer via an atomic layer deposition technique employing a first and a second precursor at a temperature in the range of 300°

C. to 500°

C. on the first electrode, the first pre-cursor being a compound having the constitutional formula M¹(R¹Cp)₂(R²)₂, wherein

M¹is one of hafnium and zirconium,

Cp is cyclopentadienyl,

R¹ is independently selected of methyl, ethyl and alkyl,

R² is independently selected of hydrogen, methyl, ethyl, alkyl, alkoxyl and halogen,

depositing the dielectric layer on the crystallization seed layer via an atomic layer deposition technique employing a third and a forth precursor wherein the third precursor being a compound having the constitutional formula M² R³ R⁴ R⁵ R⁶, wherein

M² is one of hafnium or zirconium and

R³, R⁴, R⁵, and R⁶ are independently selected of alkyl amines; and

depositing a counter electrode on the dielectric layer in the trench.