CN-122002896-A - Thin film transistor and method of manufacturing the same

CN122002896ACN 122002896 ACN122002896 ACN 122002896ACN-122002896-A

Abstract

The invention provides a thin film transistor and a manufacturing method thereof, which can regulate and control the contact performance of a source/drain and a channel in a simple and industrial compatible manner, does not need extra equipment and process steps, and does not need to change electrode materials. The thin film transistor comprises an active layer, an interface functional layer deposited on the surface of the active layer, and a source/drain electrode in contact with the active layer via the interface functional layer, wherein the interface functional layer regulates and controls fixed charges at the interface of the active layer and the source/drain electrode, so that the effective potential barrier between the active layer and the source/drain electrode is reduced by regulating and controlling the effective work function of the active layer.

Inventors

ZHANG PANTING
Wei Yanzhuo
CHEN CHEN
LI DONGDONG

Assignees

张江国家实验室

Dates

Publication Date: 20260508
Application Date: 20241101

Claims (12)

1. A thin film transistor, comprising: An active layer; An interface functional layer deposited on the surface of the active layer, and A source/drain electrode in contact with the active layer via the interface function layer, The interface functional layer regulates and controls fixed charges at the interface of the active layer and the source/drain electrode, so that the effective potential barrier between the active layer and the source/drain electrode is reduced by regulating and controlling the effective work function of the active layer.
2. The thin film transistor according to claim 1, The interface function layer comprises: A first deposition material for maintaining the effective work function of the active layer unchanged or reducing the effective work function of the active layer by introducing a fixed charge, and A second deposition material that increases an effective work function of the active layer by introducing a fixed charge, The interface functional layer regulates and controls the effective work function of the active layer by regulating and controlling the ratio of the deposition cycle number of the first deposition material to the deposition cycle number of the second deposition material.
3. The thin film transistor according to claim 2, The first deposition material is formed by circularly depositing a precursor and a first oxidant, The second deposition material is formed by circularly depositing the precursor and a second oxidant.
4. The thin film transistor according to claim 3, The interface functional layer is composed of aluminum oxide, The precursor is an organoaluminum precursor, the first oxidant is deionized water, and the second oxidant is ozone.
5. The thin film transistor according to any one of claim 1 to 4, The thickness of the interface functional layer is less than or equal to 1nm.
6. A method of manufacturing a thin film transistor, comprising: an active layer preparation step in which an active layer is prepared; an interface function layer deposition step of depositing an interface function layer on the surface of the active layer, and A source/drain electrode forming step of forming a source/drain electrode so that the source/drain electrode is in contact with the active layer via the interface function layer, In the interface function layer deposition step, fixed charges at the interface of the active layer and the source/drain electrode are regulated and controlled, so that an effective potential barrier between the active layer and the source/drain electrode is reduced by regulating and controlling an effective work function of the active layer.
7. The method for manufacturing a thin film transistor according to claim 6, wherein, The interface function layer deposition step comprises the following steps: A first deposition step in which a first deposition material is cyclically deposited on the active layer surface, the first deposition material maintaining the effective work function of the active layer unchanged or decreasing the effective work function of the active layer by introducing a fixed charge, and A second deposition step in which a second deposition material is cyclically deposited on the surface of the active layer, the second deposition material increasing the effective work function of the active layer by introducing a fixed charge, In the interface function layer deposition step, the effective work function of the active layer is regulated and controlled by regulating and controlling the ratio of the deposition cycle number in the first deposition step to the deposition cycle number in the second deposition step.
8. The method for manufacturing a thin film transistor according to claim 7, In the first deposition step, a deposition precursor and a first oxidizing agent are circulated on the active layer surface to form the first deposition material, In the second deposition step, the precursor and a second oxidizing agent are circularly deposited on the active layer surface, thereby forming the second deposition material.
9. The method for manufacturing a thin film transistor according to claim 8, The interface functional layer is composed of aluminum oxide, The precursor is an organoaluminum precursor, the first oxidant is deionized water, and the second oxidant is ozone.
10. The method for manufacturing a thin film transistor according to claim 7, And in the interface function layer deposition step, the first deposition step and the second deposition step are respectively and independently executed.
11. The method for manufacturing a thin film transistor according to claim 7, In the interfacial function layer deposition step, the first deposition step and the second deposition step are alternately performed a plurality of times.
12. The method for manufacturing a thin film transistor according to any one of claim 6 to 11, In the step of depositing the interface functional layer, the thickness of the interface functional layer is 1nm or less.

Description

Thin film transistor and method of manufacturing the same Technical Field The present invention relates to the field of semiconductor technology, and in particular, to a thin film transistor and a method for manufacturing the same. Background With the rise and development of artificial intelligence, modern society is converting to informatization, digitalization and intellectualization. The global data volume is growing in an explosive manner. According to IDC predictions, the global data volume for the next 3 years will exceed the sum of the last 30 years, with an exponential increase in demand for computational resources. Silicon-based CMOS technology relies on pure size scaling to boost integration faces significant challenges in physical principles and process technology, which makes it difficult for traditional moore's law to continue. To address the need for significant effort, it has been proposed to integrate more functions such as sensing devices, rf devices, power devices, and processors in a small space to increase the integration of the system, also known as over-the-mole technology path. On the one hand, multiple dies can be vertically stacked by packaging technology such as through silicon vias, copper interconnects and the like, so that high integration density, small occupied area, high speed and low power consumption are realized, which is commonly called 3D integration. The number of commercial applications employing this technology has steadily increased. For example, commercial FPGAs and GPUs are available on the market that employ 2.5D integration based on intermediaries (intermediaries) to increase density, significantly reducing interconnect overhead. On the other hand, a plurality of transistor layers can be stacked on a single substrate, so that monolithic 3D integration is realized. Compared with the packaging technology, the monolithic 3D integration can directly grow the active layer by utilizing a subsequent process, so that higher integration density and high-bandwidth communication can be realized. The key to monolithic 3D integration is the development of a later compatible active (e.g., transistor) device process. Oxide semiconductors (such as indium gallium zinc oxide, indium oxide, zinc oxide and the like) thin film transistors (OS-TFTs) have the advantages of low thermal budget (< 400 ℃) and compatibility with subsequent processes, mature large-scale deposition process, good electrical performance (extremely low leakage current, higher mobility and the like, and are important technical approaches for realizing monolithic 3D integration. Under advanced nodes, transistor dimensions are continually shrinking, and in order to ensure uniform deposition of thin films under advanced nodes, ALD fabrication techniques are required to ensure uniformity of low thickness (on the order of a few nanometers) films and conformality in complex structures. Under advanced nodes, it becomes increasingly difficult to effectively regulate the contact of the source/drain and the channel in the OS-TFT. And the contact properties of the source/drain and the channel directly affect the electrical properties (e.g., mobility, etc.) of the device. Conventionally, in order to improve the contact performance between a source/drain and a channel, two control methods have been proposed, namely (1) locally doping the portion of the channel in contact with the source/drain to improve the conductivity thereof and (2) using an electrode material having higher conductivity. By the two regulation modes, the contact performance between the source/drain and the channel can be improved to a certain extent, so that the electrical performance of the device is improved. Disclosure of Invention The invention aims to solve the technical problems Although the existing control mode can improve the contact performance between the source/drain and the channel to a certain extent, the following problems still exist. For the above regulation mode (1), since additional doping processes and processes such as doping activation (e.g. annealing) are required, there is a certain process complexity and the manufacturing cost of the device will be increased. With the above-described control scheme (2), since the types of electrode materials compatible with the semiconductor industry process are limited, it is difficult to exchange them at will, and therefore, the difficulty of obtaining better contact performance by exchanging them for an electrode material having higher conductivity is increased. The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a thin film transistor and a method for manufacturing the same, which can control the contact performance between a source/drain and a channel in a simple and industrial compatible manner, without requiring additional equipment and process steps, and without replacing an electrode material. Technical proposal ado