CN-122028443-A - Preparation method of hafnium oxide-based MIM capacitor and hafnium oxide-based MIM capacitor

Abstract

The invention adopts the nitrogen doped hafnium oxide as the dielectric layer of the MIM capacitor, can improve the phase transition temperature of the capacitor dielectric layer, can reach 1000 ℃, can reduce electric leakage at high phase transition temperature, improves the high temperature resistance of the MIM capacitor, improves the reliability, can improve the dielectric constant of the hafnium oxide by doping nitrogen, further improves the device performance, can improve the annealing temperature of the hafnium oxide by improving the phase transition temperature of the hafnium oxide, further reduces the annealing time, and improves the performance of the hafnium oxide material.

Inventors

• Hu Shuhuai
• CHEN LIN
• FAN ZHIYING

Assignees

• 格科半导体(上海)有限公司

Dates

Publication Date

20260512

Application Date

20241111

Claims (10)

1. 1. A method of making a hafnium oxide-based MIM capacitor comprising: providing a substrate; forming a lower pole plate layer on the substrate; Forming a hafnium oxide layer on the lower plate layer, and then carrying out nitrogen doping to improve the phase transition temperature of the hafnium oxide layer; An upper pole plate layer is formed on the nitrogen doped hafnium oxide layer.
2. 2. The method of claim 1, wherein the phase transition temperature exceeds 600 ℃.
3. 3. The method of claim 2, wherein the hafnium oxide is formed by Atomic Layer Deposition (ALD), metal organic vapor deposition (MOCVD), chemical Vapor Deposition (CVD), or Physical Vapor Deposition (PVD).
4. 4. The method of claim 2, wherein the nitrogen doping is by Decoupled Plasma Nitridation (DPN), rapid thermal nitrogen doping (RTN), furnace nitrogen doping, remote plasma nitrogen doping (RPN), or well implantation.
5. 5. The method of claim 4, wherein the nitrogen doping is by Decoupled Plasma Nitridation (DPN) using a gas comprising N 2 or N x O y , wherein x is greater than 0 and y is greater than 0.
6. 6. The method of claim 5, wherein the nitrogen doped hafnium oxide layer is formed followed by a post nitridation anneal (Decoupled Plasma Nitridation, DPN) process.
7. 7. The method of claim 6, wherein the annealing temperature is above a phase transition temperature of undoped hafnium oxide and below a phase transition temperature of nitrogen doped hafnium oxide.
8. 8. The method of claim 1, wherein the lower plate layer and the lower plate layer are selected from one or more of titanium, tantalum, titanium nitride, tantalum nitride, copper, and tungsten.
9. 9. The method of claim 1, wherein the MIM capacitor is used in a CMOS image sensor chip.
10. 10. A hafnium oxide based MIM capacitor prepared by the method of any one of claims 1 to 9.

Description

Preparation method of hafnium oxide-based MIM capacitor and hafnium oxide-based MIM capacitor Technical Field The invention relates to the technical field of semiconductors, in particular to a method for forming a MIM capacitor and a hafnium oxide base MIM capacitor. Background Existing capacitors can be broadly divided into a front-side capacitor, such as a MOS capacitor, a PN junction capacitor, and a back-side capacitor, such as a MIM (metal layer-insulator layer-metal layer) capacitor, a MOM (metal layer-oxide layer-metal layer) capacitor. The MIM capacitor provides better frequency and temperature related characteristics, and can be formed in inter-layer metal and copper interconnect processes, reducing the difficulty and complexity of integration with CMOS front-end processes, and is therefore widely used in various integrated circuits such as analog-logic, analog-digital, mixed signal and radio frequency circuits, particularly CMOS image sensor (CMOS image sensor, CIS) chips. The MIM capacitor structure generally includes a capacitor bottom plate (metal layer), a capacitor dielectric layer (insulating layer) and a capacitor top plate (metal layer), which form a sandwich structure with an insulating dielectric layer sandwiched between two metal electrodes. Hafnium oxide materials are used in the preparation of capacitor dielectric layers due to their relatively high dielectric constants. In the conventional CMOS image sensor manufacturing process, a process with a temperature of 450 ℃ or higher is required, however, under the high temperature condition, amorphous hafnium oxide in the MIM capacitor undergoes phase transition, and the phase transition hafnium oxide becomes a fast channel for oxygen or impurity diffusion, so that electric leakage is caused, and the performance and reliability of the device are seriously damaged. Therefore, increasing the transformation temperature of hafnium oxide, and thus the high temperature resistance of the capacitor, is a technical key point to be solved by those skilled in the art. Disclosure of Invention Based on the above-described problems, the present invention proposes a method for manufacturing a hafnium oxide-based MIM capacitor and a hafnium oxide-based capacitor. On one hand, the preparation method of the hafnium oxide-based MIM capacitor comprises the steps of providing a substrate, forming a lower electrode plate layer on the substrate, forming a hafnium oxide layer on the lower electrode plate layer, then carrying out nitrogen doping to improve the phase transition temperature of the hafnium oxide layer, and forming an upper electrode plate layer on the nitrogen doped hafnium oxide layer. Optionally, the phase transition temperature exceeds 600 ℃. Alternatively, hafnium oxide is formed by Atomic Layer Deposition (ALD), metal organic vapor deposition (MOCVD), chemical Vapor Deposition (CVD), or Physical Vapor Deposition (PVD). Optionally, the nitrogen doping is by Decoupled Plasma Nitridation (DPN), rapid thermal nitrogen doping (RTN), in-furnace nitrogen doping, remote plasma nitrogen doping (RPN), or well implantation. Optionally, the nitrogen doping is performed by Decoupled Plasma Nitridation (DPN), and the gas used includes N 2 or N xOy, where x is greater than 0 and y is greater than 0. Optionally, a post-nitridation anneal (Decoupled Plasma Nitridation, DPN) process is performed after the formation of the nitrogen-doped hafnium oxide layer. Optionally, the annealing temperature is above the phase transition temperature of undoped hafnium oxide and below the phase transition temperature of nitrogen doped hafnium oxide. Optionally, the lower electrode plate layer and the lower electrode plate layer are selected from one or more than two of titanium, tantalum, titanium nitride, tantalum nitride, copper and tungsten. Alternatively, the MIM capacitor is applied in a CMOS image sensor chip. In a second aspect, the present invention provides a hafnium oxide based MIM capacitor prepared by the above-described method. Compared with the prior art, the technical scheme of the invention has the following beneficial effects: The MIM capacitor adopts the nitrogen doped hafnium oxide as the capacitor dielectric layer, so that the phase transition temperature of the capacitor dielectric layer can be increased to 1000 ℃, the electric leakage can be reduced by the high phase transition temperature, the high temperature resistance of the MIM capacitor is improved, the reliability of the MIM capacitor is improved, the dielectric constant of the hafnium oxide is improved by doping nitrogen, the device performance is further improved, the annealing temperature of the hafnium oxide can be improved by improving the phase transition temperature of the hafnium oxide, the annealing time is further shortened, and the performance of the hafnium oxide material is improved. Drawings The accompanying drawings, which are included to provide a further understanding of the inventi