Phase-change random access memory and method of manufacturing the same

1. A phase-change random access memory (PCRAM) device, comprising:

a semiconductor substrate; and

a PN diode formed on the semiconductor substrate and including a layer interposed therein to suppress thermal diffusion of ions,

wherein the PN diode includes:

a first polysilicon pattern layer having a first conductivity type material;

a second polysilicon pattern layer formed on the first polysilicon pattern layer; and

a third polysilicon pattern layer formed on the second polysilicon pattern layer and having a second conductivity type material.

2. The PCRAM device of claim 1 , wherein the second polysilicon pattern layer comprising a silicon carbon (SiC) layer.

3. The PCRAM device of claim 1 , wherein the second polysilicon pattern layer comprising a polysilicon layer containing carbon (C).

4. The PCRAM device of claim 1 , wherein the second conductivity type material is a P type if the first conductivity type material is an N type, while the second conductivity type material is an N type if the first conductivity type is a P type.

5. A method of manufacturing a phase-change random access memory (PCRAM) device, the method comprising:

providing a semiconductor substrate; and

forming a PN diode pattern including a layer interposed therein to suppress thermal diffusion of ions, on the semiconductor substrate,

wherein the forming a PN diode pattern includes:

forming a first polysilicon layer is formed over the semiconductor substrate;

forming a second polysilicon layer on the first polysilicon layer; and

forming a third polysilicon layer on the second polysilicon layer.

6. The method of claim 5 , wherein the second polysilicon layer comprising a silicon carbon (SiC) layer.

7. The method of claim 6 , wherein the SiC layer is formed by ion-implanting a SiC material.

8. The method of claim 5 , wherein the second silicon layer comprising a polysilicon layer including carbon (C).

9. The method of claim 8 , wherein the polysilicon layer containing carbon (C) is formed by depositing a carbon material in an in-situ deposition method.

10. The method of claim 5 , wherein forming a second polysilicon layer includes forming the second polysilicon layer by a method using low pressure chemical vapor deposition (LPCVD) equipment, very low pressure CVD (VLPCVD) equipment, plasma-enhanced CVD (PECVD) equipment, ultrahigh vacuum CVD (UHVCVD) equipment, rapid thermal CVD (RTCVD) equipment, or atmosphere pressure CVD (APCVD) equipment.

11. The method of claim 5 , wherein forming a PN diode pattern includes patterning the first polysilicon layer, the second polysilicon layer, and the third polysilicon layer sequentially stacked to form a vertical type pattern.

12. The method of claim 5 , wherein the third polysilicon layer includes a second conductivity type material if the first polysilicon layer includes a first conductivity type material.

13. The method of claim 12 , wherein the second conductivity type material is a P type if the first conductivity type material is an N type, while the second conductivity type material is an N type if the first conductivity type material is a P type.

14. A phase-change random access memory (PCRAM) device, comprising:

a semiconductor substrate; and

a PN diode formed on the semiconductor substrate and including a layer interposed therein to suppress thermal diffusion of ions,

wherein the layer includes a polysilicon layer containing a carbon (C) material.

15. The PCRAM device of claim 14 , wherein the PN diode includes:

an n-type polysilicon layer formed on the semiconductor substrate; and

a p-type polisilicon layer formed over the n-type polysilicon layer,

wherein the layer is formed between the n-type polysilicon layer and the p-type polysilicon layer.

16. The PCRAM device of claim 14 , wherein the layer is silicon carbon layer.