KR100427715B1 - Magnetoresistive RAM and manufacturing method therefor - Google Patents

Abstract

The present invention relates to a magnetoresistive RAM and a method of manufacturing the same, wherein a read word line and a write word line are formed in the same unit process in a gate process of a transistor, and the read word line and the write word line are the same. It is formed in a similar layer. Therefore, the process can be improved while simplifying the structure of the magnetoresistive ram.

Description

Magnetoresistive ram and manufacturing method therefor {Magnetoresistive RAM and manufacturing method therefor}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetoresistive ram and a method of manufacturing the same, and more particularly, to a magnetoresistive ram and a method of manufacturing a read / write wordline in the same unit process by improving the arrangement of wordlines.

Most semiconductor memory manufacturers are developing magnetoresistive RAMs using ferromagnetic materials as one of the next generation memory devices. Magnetoresistive RAM is a type of memory that stores a magnetic polarization state in a thin film of magnetic material. It can be used by changing or sensing the magnetic polarization state by a magnetic field generated by a combination of bit line current and word line current. A read operation is performed.

Such magnetoresistive RAM is generally composed of various cell types such as Giant Magneto Resistance (GMR) and Magnetic Tunnel Junction (MTJ). That is, the magnetoresistive RAM implements a memory device by using a giant magnetoresistance (GMR) phenomenon or spin polarization magnetic permeation phenomenon, which occurs because spin has a great influence on the electron transfer phenomenon. First, a magnetoresistive RAM using a giant magnetoresistance (GMR) phenomenon is implemented by using a phenomenon in which the resistance in the case where the spin directions are different in the two magnetic layers having a nonmagnetic layer between them is significantly different. In addition, the magnetoresistive RAM using the spin polarization magnetic permeation phenomenon is implemented by using the phenomenon that current transmission occurs much better than the case where the spin direction is the same in the two magnetic layers having the insulating layer interposed therebetween.

1 shows a cross-sectional view of such a conventional magnetoresistive ram.

In the structure of the conventional magnetoresistive RAM, an insulating layer 13 for device isolation is formed on a P-type substrate 11, and a drain contact region 15a and a source contact region are formed between the insulating layers 13. A contact region having an N + region for forming 15b and a P + region for forming gate contact region 16 is formed. The word line 19 is formed on the gate contact region 16. In addition, a conductive layer 17a is formed on the drain contact region 15a, respectively, and a ground conductive layer 17b is formed on the source contact region 15b. The contact plug 21a, the conductive layer 23a, the contact plug 27, and the seed layer 29 are formed on the conductive layer 17a, respectively.

The ground contact plug 21b and the ground conductive layer 23b are formed on the ground conductive layer 17b. An MTJ 31 including a fixed ferromagnetic layer, a tunnel junction layer, and a variable ferromagnetic layer is formed on the seed layer 29, and a bit line 33 is formed on the MTJ 31.

After the process of forming the read word line 19 formed on the gate of the MOS transistor, the write word line 25 is separately formed.

The conventional magnetoresistive RAM having such a structure has a 1 T + 1 MTJ structure having one MOS transistor T and one MTJ. The structure of the magnetoresistive RAM using the MOS transistors T and MTJ includes a read word line connected to a gate and a write word line for writing data to the MTJ to read the bit line data.

However, in the conventional magnetoresistive RAM as described above, since the metal wiring process for forming the read word line and the metal wiring process for forming the write word line are performed in separate unit processes, a complicated multi-step process is required accordingly. There is also a disadvantage in terms of cell size.

SUMMARY OF THE INVENTION The present invention was created to solve the above problems, and has an object of simplifying a magnetoresistive RAM manufacturing process by forming a read word line and a write word line in the same unit process.

Another object of the present invention is to form a read word line and a write word line in the same or similar position so that the magnetoresistive RAM has an advantageous structure in terms of cell size.

1 is a cross-sectional view of a structure of a conventional magnetoresistive ram.

2 is a cross-sectional view of the structure of the magnetoresistive ram according to the present invention;

The magnetoresistive RAM according to the present invention for achieving the above object is a MOS transistor having a gate contact region, a source and a drain region formed on a semiconductor substrate, and a first word line and a second word line formed on the MOS transistor It is characterized in that formed on the same process line.

The magnetoresistive RAM of the present invention includes a MOS transistor having a gate contact region, a source and a drain region formed on a semiconductor substrate, an insulating layer formed on the semiconductor substrate to form a line such as a MOS transistor, and a first formed on the MOS transistor. And a second word line stacked on the first word line and the insulating layer to form the same process line as the first word line.

Hereinafter, with reference to the accompanying drawings will be described in detail an embodiment of the present invention.

2 shows a cross-sectional view of a magnetoresistive ram according to the present invention.

Looking at the structure, in the magnetoresistive RAM according to the present invention, an insulating layer 102 for device isolation is formed on the P-type substrate 100, and the drain contact region 104a and the source contact are formed between the insulating layers 102. A MOS transistor having an N + region for forming the region 104b and a P + region for forming the gate contact region 105 is formed. A read word line 108 is formed on the gate contact region 105. In addition, a first conductive layer 106a is formed on the drain contact region 104a, and a grounding second conductive layer 106b is formed on the source contact region 106b.

Here, a write word line 110 is formed on the insulating layer 102, and the write word line 110 has the same height as the read word line 108 formed in the gate 105 of the MOS transistor. . In addition, a first contact plug 112 and a seed layer 114 are formed on the first conductive layer 106a, respectively. The MTJ 116 including the fixed ferromagnetic layer, the tunnel junction layer, and the variable ferromagnetic layer is stacked on the seed layer 114, and a bit line 118 is formed on the MTJ 116.

Therefore, during read, the current of the bit line is sensed by the read word line 108, and when written, current is applied to the write word line 110 so that the magnetic layer spin direction of the MTJ 116 is determined so that data is stored. Stored.

According to the embodiment, the word lines for reading 108 and the word lines for writing 110 are formed to have the same or similar heights while being disposed at different positions in a plane. The word line 108 for reading and the word line 110 for writing are mainly made of a material such as polysilicon, and their materials are the same. Therefore, the write word line 110 can be formed together when the read word line 108 is formed on the gate contact region 105. Therefore, these read word lines 108 and write word lines can be formed together. The 110 may be formed by the same unit process, that is, the gate electrode forming process.

In addition, although the read word line 108 and the write word line 110 are disposed at different positions in plan view, the write word line 110 should be formed dependently under the formation position of the MTJ 116. This is to effectively change the magnetic layer spin direction of the MTJ 116 as a magnetic field generated when current flows in the write word line 110. Therefore, the write word line 110 may be formed on the insulating layer for device isolation depending on the position of the MTJ 116.

As described above, the present invention simplifies the manufacturing process of the magnetoresistive ram by forming the read word line process and the write word line in the same unit process in the gate process of the transistor, and the structure of the magnetoresistive ram is reduced in cell size. It provides an effect that can be advantageously improved in terms of.

Claims (5)

A MOS transistor having a read word line; A write word line provided on the same layer as the read word line; An MTJ spaced apart from the write word line and connected to a source contact region of the MOS transistor; And And a bit line electrically connected to the MTJ. delete The method of claim 1, And the word line for writing is formed on an insulating layer for device isolation. In the method of manufacturing a magnetoresistive RAM comprising a transistor and MJT, The read word line formed in the gate region of the transistor and the write word line formed under the MTJ are formed in the same unit process. The method of claim 4, wherein Wherein said unit process is a process of forming a gate electrode of said transistor.