An exemplary system may include a chamber configured to contain a semiconductor substrate in a processing region of the chamber. The system may include a first remote plasma unit fluidly coupled with a first access of the chamber and configured to deliver a first precursor into the chamber through the first access. The system may still further include a second remote plasma unit fluidly coupled with a second access of the chamber and configured to deliver a second precursor into the chamber through the second access. The first and second access may be fluidly coupled with a mixing region of the chamber that is separate from and fluidly coupled with the processing region of the chamber. The mixing region may be configured to allow the first and second precursors to interact with each other externally from the processing region of the chamber.

Semiconductor processing systems having multiple plasma configurations

Systems, chambers, and processes are provided for controlling process defects caused by moisture contamination. The systems may provide configurations for chambers to perform multiple operations in a vacuum or controlled environment. The chambers may include configurations to provide additional processing capabilities in combination chamber designs. The methods may provide for the limiting, prevention, and correction of aging defects that may be caused as a result of etching processes performed by system tools.

Processing systems and methods for halide scavenging

Methods of etching exposed titanium nitride with respect to other materials on patterned heterogeneous structures are described, and may include a remote plasma etch formed from a fluorine-containing precursor. Precursor combinations including plasma effluents from the remote plasma are flowed into a substrate processing region to etch the patterned structures with high titanium nitride selectivity under a variety of operating conditions. The methods may be used to remove titanium nitride at faster rates than a variety of metal, nitride, and oxide compounds.

Selective titanium nitride etching

Methods are described herein for etching metal films which are difficult to volatize. The methods include exposing a metal film to a chlorine-containing precursor (e.g. Cl 2 ). Chlorine is then removed from the substrate processing region. A carbon-and-nitrogen-containing precursor (e.g. TMEDA) is delivered to the substrate processing region to form volatile metal complexes which desorb from the surface of the metal film. The methods presented remove metal while very slowly removing the other exposed materials. A thin metal oxide layer may be present on the surface of the metal layer, in which case a local plasma from hydrogen may be used to remove the oxygen or amorphize the near surface region, which has been found to increase the overall etch rate.

Oxide and metal removal

A method of etching carbon films on patterned heterogeneous structures is described and includes a gas phase etch using remote plasma excitation. The remote plasma excites a fluorine-containing precursor and an oxygen-containing precursor, the plasma effluents created are flowed into a substrate processing region. The plasma effluents etch the carbon film more rapidly than silicon, silicon nitride, silicon carbide, silicon carbon nitride and silicon oxide.

Low temperature gas-phase carbon removal

Transistors and their methods of formation are described. Low dielectric constant material (e.g. a void) is placed between an elongated gate and a contact to increase the attainable switching speed of the gate of the device. An elongated structural slab of silicon nitride is temporarily positioned on both sides of the gate. Silicon oxide is formed over the silicon nitride slabs and the gate. Contacts are formed through the silicon oxide. The silicon oxide is selectively etched back to expose the silicon nitride slab. A portion or all the silicon nitride slab is removed and replaced with low-K dielectric or any dielectric with an air-gap to enable higher switching speed of the transistor. The highly-selective silicon nitride etch uses remotely excited fluorine and a very low electron temperature in the substrate processing region.

Feol low-k spacers

There has been a steady increase in sub-nm precision requirement for many critical plasma etching processes in the semiconductor industry. In addition to high selectivity and low controllable etch rate, an important requirement of atomic precision etch processes is no (or minimal) damage to the remaining material surface. It has traditionally not been possible to avoid damage in conventional radio-frequency (RF) plasma processing systems, even during layer-by-layer or 'atomic layer' etch. To meet these increasingly stringent requirements, it is necessary to have an accurate control over ion energy and ion/radical composition during plasma processing. In this work, a new plasma etch system designed to facilitate atomic precision plasma processing is presented. An electron sheet beam parallel to the substrate surface is used to produce a plasma in this system. This plasma has a significantly lower electron temperature T e ~ 0.3 eV and ion energy E i < 3 eV (without applied bias) compared to inductively and capacitively coupled RF plasmas. Electron beam plasmas also have a higher ion–to–radical ratio compared to RF plasmas, so this plasma etch system employs an independent radical source for accurate control over relative ion and radical concentrations. A low frequency RF bias capability that allows control of ion energy in the 2–50 eV range is another important component of this plasma etch system. The results of etching of a variety of materials and structures in this low-electron temperature plasma system are presented in this study: (1) layer-by-layer etching of p-Si at E i ~ 25–50 eV using electrical and gas cycling is demonstrated; (2) continuous etching of epi-grown µ-Si in Cl2-based plasmas is performed, showing that surface damage can be minimized by keeping E i < 10 eV. Also presented are the results of molecular dynamics modeling of atomic precision etching at low E i.

https://iopscience.iop.org/article/10.1088/1361-6463/aa7357/pdf

Etching with atomic precision by using low electron temperature plasma

In a plasma reactor for processing a workpiece, an electron beam is employed as the plasma source, and a remote radical source is incorporated with the process chamber.

Electron beam plasma source with remote radical source

Sub-nm precision is increasingly being required of many critical plasma etching processes in the semiconductor industry. Accurate control over ion energy and ion/radical composition is needed during plasma processing to meet these stringent requirements. Described in this work is a new plasma etch system which has been designed with the requirements of atomic precision plasma processing in mind. In this system, an electron sheet beam parallel to the substrate surface produces a plasma with an order of magnitude lower electron temperature Te (~ 0.3 eV) and ion energy Ei (< 3 eV without applied bias) compared to conventional radio-frequency (RF) plasma technologies. Electron beam plasmas are characterized by higher ion-to-radical fraction compared to RF plasmas, so a separate radical source is used to provide accurate control over relative ion and radical concentrations. Another important element in this plasma system is low frequency RF bias capability which allows control of ion energy in the 2-50 eV range. Presented in this work are the results of etching of a variety of materials and structures performed in this system. In addition to high selectivity and low controllable etch rate, an important requirement of atomic precision etch processes is no (or minimal) damage to the remaining material surface. It has traditionally not been possible to avoid damage in RF plasma processing systems, even during atomic layer etch. The experiments for Si etch in Cl2 based plasmas in the aforementioned etch system show that damage can be minimized if the ion energy is kept below 10 eV. Layer-by-layer etch of Si is also demonstrated in this etch system using electrical and gas pulsing.

Atomic precision etch using a low-electron temperature plasma

The disclosure concerns a method of operating a plasma reactor having an electron beam plasma source for independently adjusting electron beam energy, plasma ion energy and radical population The disclosure further concerns an electron beam source for a plasma reactor having an RF-driven electrode for producing the electron beam

Ying Zhang

Papers

Feol low-k spacers

Etching with atomic precision by using low electron temperature plasma

Electron beam plasma source with remote radical source

Atomic precision etch using a low-electron temperature plasma

Low electron temperature etch chamber with independent control over plasma density, radical composition and ion energy for atomic precision etching