Silicon integrated BTO film and preparation method thereof

Abstract

The invention discloses a silicon integrated BTO film and a preparation method thereof, the silicon integrated BTO film comprises a Si substrate, an 8Al2O3:96HfO2 transition layer and a BaTiO3 film, the 8Al2O3:96HfO2 transition layer is arranged on the surface of the Si substrate, and the BaTiO3 film is arranged on the surface of the 8Al2O3:96HfO2 transition layer; the manufacturing method comprises the following steps: growing the 8Al2O3:96HfO2 transition layer on the Si substrate by adopting an atomic layer deposition method; and growing a BaTiO3 film on the 8Al2O3:96HfO2 transition layer byadopting a radio frequency magnetron sputtering method, and annealing after the radio frequency magnetron sputtering is finished to obtain the silicon integrated BTO film. According to the film, theferroelectric property of the film on the silicon substrate is greatly improved, and the fatigue property and the wide-temperature broadband property of the film are also maintained at a relatively high level.

Description

Technical field

[0001] The present invention relates to the field of ferroelectric thin film devices and manufacturing methods thereof, especially capacitors or storage devices, and in particular to a silicon integrated BTO film and a manufacturing method thereof.Background technique

[0002] The preparation of ferroelectric thin films with excellent properties on silicon wafers is very important for microelectronics industrial applications. In a metal ferroelectric semiconductor field effect transistor (MFS-FET), a ferroelectric thin film is used as a gate insulator. Storage devices made of ferroelectric thin films (ferroelectric random access memory FRAM and DRAM) are also research hotspots. Barium titanate (BaTiO3, BTO) as a typical ferroelectric material, due to its excellent ferroelectricity, electro-optical and nonlinear optical properties, it has been used in storage devices, multilayers, optoelectronic devices, infrared detectors and other applications. Application and attention, ...

Examples

preparation example Construction

[0040]The preparation method of the silicon integrated BTO film of the present invention includes the following steps.

[0041](1) Si substrate processing

[0042]The Si substrate was immersed in hydrofluoric acid and deionized water successively for cleaning to remove impurities and natural oxide layer on the surface of the Si substrate, and then dried with high-pressure nitrogen and sent to the vacuum deposition chamber of the atomic layer deposition equipment. On the sample stage.

[0043](2) 8Al2O3:96HfO2Preparation of the transition layer

[0044]Using atomic layer deposition method to grow 8Al with preset thickness on Si substrate2O3:96HfO2Transition layer.

[0045](3)BaTiO3Film preparation

[0046]Using radio frequency magnetron sputtering method in 8Al2O3:96HfO2Fixed time growth of BaTiO on the transition layer3film. Radio frequency magnetron sputtering uses BaTiO3Target material, the background vacuum in the magnetron sputtering chamber is better than 10-5mbar, the working gas is a mixed gas...

Embodiment

[0050]The method for preparing the silicon integrated BTO film of this embodiment includes the following steps:

[0051](1) Si substrate processing

[0052]A P-type (100) Si wafer doped with boron is selected. Immerse briefly in hydrofluoric acid with a solute volume fraction of 2% to remove SiO on the surface of the Si substrate2Oxide layer and other impurities; then quickly rinse with deionized water to remove residual hydrofluoric acid; then use high-pressure nitrogen to dry the substrate and send it to the vacuum deposition chamber of the atomic layer deposition equipment and place it on the sample table.

[0053](2) 8Al2O3:96HfO2Transition layer preparation

[0054]Using atomic layer deposition method to grow 8Al with preset thickness on Si substrate2O3:96HfO2Transition layer. Using the conditions shown in Table 1, change HfO2Cycle and Al2O3Cyclic deposition sequence to grow HfO on Si substrate2:Al2O38Al with a cycle ratio of 96:8 and a thickness of 13nm2O3:96HfO2Transition layer.

[0055]Tab...

Technical field

[0001] The present invention relates to the field of ferroelectric thin film devices and manufacturing methods thereof, especially capacitors or storage devices, and in particular to a silicon integrated BTO film and a manufacturing method thereof.Background technique

[0002] The preparation of ferroelectric thin films with excellent properties on silicon wafers is very important for microelectronics industrial applications. In a metal ferroelectric semiconductor field effect transistor (MFS-FET), a ferroelectric thin film is used as a gate insulator. Storage devices made of ferroelectric thin films (ferroelectric random access memory FRAM and DRAM) are also research hotspots. Barium titanate (BaTiO3, BTO) as a typical ferroelectric material, due to its excellent ferroelectricity, electro-optical and nonlinear optical properties, it has been used in storage devices, multilayers, optoelectronic devices, infrared detectors and other applications. Application and attention, ...

Examples

preparation example Construction

[0040]The preparation method of the silicon integrated BTO film of the present invention includes the following steps.

[0041](1) Si substrate processing

[0042]The Si substrate was immersed in hydrofluoric acid and deionized water successively for cleaning to remove impurities and natural oxide layer on the surface of the Si substrate, and then dried with high-pressure nitrogen and sent to the vacuum deposition chamber of the atomic layer deposition equipment. On the sample stage.

[0043](2) 8Al2O3:96HfO2Preparation of the transition layer

[0044]Using atomic layer deposition method to grow 8Al with preset thickness on Si substrate2O3:96HfO2Transition layer.

[0045](3)BaTiO3Film preparation

[0046]Using radio frequency magnetron sputtering method in 8Al2O3:96HfO2Fixed time growth of BaTiO on the transition layer3film. Radio frequency magnetron sputtering uses BaTiO3Target material, the background vacuum in the magnetron sputtering chamber is better than 10-5mbar, the working gas is a mixed gas...

Embodiment

[0050]The method for preparing the silicon integrated BTO film of this embodiment includes the following steps:

[0051](1) Si substrate processing

[0052]A P-type (100) Si wafer doped with boron is selected. Immerse briefly in hydrofluoric acid with a solute volume fraction of 2% to remove SiO on the surface of the Si substrate2Oxide layer and other impurities; then quickly rinse with deionized water to remove residual hydrofluoric acid; then use high-pressure nitrogen to dry the substrate and send it to the vacuum deposition chamber of the atomic layer deposition equipment and place it on the sample table.

[0053](2) 8Al2O3:96HfO2Transition layer preparation

[0054]Using atomic layer deposition method to grow 8Al with preset thickness on Si substrate2O3:96HfO2Transition layer. Using the conditions shown in Table 1, change HfO2Cycle and Al2O3Cyclic deposition sequence to grow HfO on Si substrate2:Al2O38Al with a cycle ratio of 96:8 and a thickness of 13nm2O3:96HfO2Transition layer.

[0055]Tab...

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