METHOD OF DEPOSITING NANOLAMINATE FILM FOR NON-VOLATILE FLOATING GATE MEMORY DEVICES BY ATOMIC LAYER DEPOSITION

• US 20080054332A1
• Filed: 08/29/2007
• Published: 03/06/2008
• Est. Priority Date: 08/30/2006
• Status: Active Grant

• Current Assignee: Korea Research Institute of Chemical Technology
• Original Assignee: Korea Research Institute of Chemical Technology
• Inventors: LEE, Young-Kuk, CHO, Won-Tae, LEE, Sun-Sook, KIM, Chang-Gyoun, AN, Ki-Seok, CHUNG, Taek-Mo
• Granted Patent: US 7,659,215 B2
• Time in Patent Office: Days
• US Class Current: 257/315
• CPC Class Codes: H01L 21/02175 characterised by the metal H01L21/02197 takes precedence
• CPC Class Codes: H01L 21/02178 the material containing aluminium, e.g. Al2O3
• CPC Class Codes: H01L 21/02181 the material containing hafnium, e.g. HfO2
• CPC Class Codes: H01L 21/02189 the material containing zirconium, e.g. ZrO2
• CPC Class Codes: H01L 21/022 the layer being a laminate, i.e. composed of sublayers, e.g. stacks of alternating high-k metal oxides adhesion layers or buffer layers H01L21/02304, H01L21/02362
• CPC Class Codes: H01L 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD
• CPC Class Codes: H01L 21/3142 of nano-laminates, e.g. alternating layers of Al203-Hf02
• CPC Class Codes: H01L 21/3162 on a silicon body
• CPC Class Codes: H01L 29/40117 the electrodes comprising a charge-trapping insulator

Abstract

Disclosed herein is a method of depositing a nanolaminate film for next-generation non-volatile floating gate memory devices by atomic layer deposition. The method includes the steps of: introducing a substrate into an atomic layer deposition reactor; forming on the substrate a first high-dielectric-constant layer by alternately supplying an oxygen source and a metal source selected from among an aluminum source, a zirconium source and a hafnium source; forming on the first high-dielectric-constant layer a nickel oxide layer by alternately supplying a nickel source and an oxygen source; and forming on the nickel oxide layer a second high-dielectric-constant layer by alternately supplying an oxygen source and a metal source selected from among an aluminum source, a zirconium source and a hafnium source. The nanolaminate film deposited according to the method shows good memory window characteristics compared to those of memory devices fabricated using nanocrystal floating gates according to the prior physical vapor deposition methods, and thus can be applied to non-volatile floating gate memory devices.

Claims

1. A method for depositing a nanolaminate film for non-volatile floating gate memory devices, the method comprising the steps of:

a) introducing a substrate into an atomic layer deposition reactor;

b) forming on the substrate a first high-dielectric-constant layer by alternately supplying an oxygen source and a metal source selected from among an aluminum source, a zirconium source and a hafnium source;

c) forming on the first high-dielectric-constant layer a nickel oxide layer by alternately supplying a nickel source and an oxygen source; and

d) forming on the nickel oxide layer a second high-dielectric-constant layer by alternately supplying an oxygen source and a metal source selected from among an aluminum source, a zirconium source and a hafnium source.

2. The method of claim 1, wherein the first high-dielectric-constant layer and the second high-dielectric-constant layer consist of an aluminum oxide layer.

3. The method of claim 1, wherein nickel aminoalkoxide, represented by Formula 1, is used as the nickel source for forming the nickel oxide layer:

wherein m is an integer ranging from 1 to 3, and R and R′

, which may be the same or different, represent a linear or branched-chain C₁-C₄ alkyl group.

4. The method of claim 3, wherein m in Formula 1 is 1 or 2.

5. The method of claim 1, wherein the nickel source is one compound selected from among nickel chloride (NiCl₂), Ni(acac)₂ (acac=acetylacetonato), Ni(tmhd)₂ (tmhd=2,2,6,6-tetramethyl-3,5-heptanedioato), Ni(dmg)₂ (dmg=dimethylglyoximato) and Ni(apo)₂ (apo=2-amino-pent-2-en-4-onato).

6. The method of claim 1, wherein the oxygen source is water, oxygen, ozone, or oxygen plasma.

7. The method of claim 1, wherein the substrate is maintained at a temperature of 90-200°

C.

8. The method of claim 1, further comprising, after the step d), a step of thermally treating the substrate at a temperature of 400-1000°

C.

9. A non-volatile floating gate memory device, comprising:

a semiconductor substrate;

a first high-dielectric-constant layer formed on the semiconductor substrate by atomic layer deposition;

a nickel oxide layer formed on the first high-dielectric-constant layer by atomic layer deposition;

a second high-dielectric-constant layer formed on the nickel oxide layer by atomic deposition layer; and

an electrode formed on the second high-dielectric-constant layer.

10. The non-volatile floating gate memory device of claim 9, wherein the first high-dielectric-constant layer and the second high-dielectric-constant layer consist of one selected from among an aluminum oxide layer, a zirconium oxide layer and a hafnium oxide layer.

11. The non-volatile floating gate memory device of claim 10, wherein the first high-dielectric-constant layer and the second high-dielectric-constant layer consist of the aluminum oxide layer.

12. The non-volatile floating gate memory device of claim 9, wherein the electrode is made of one selected from among poly-silicon (Si), aluminum (Al), platinum (Pt), iridium (Ir), ruthenium (Ru), nickel silicide (Ni₂Si), indium tin oxide (ITO), and ruthenium oxide (RuO₂).