A method for selectively etching a silicon nitride layer on a substrate includes arranging a substrate on a substrate support of a substrate processing chamber The substrate processing chamber includes an upper chamber region, an inductive coil arranged outside of the upper chamber region, a lower chamber region including the substrate support and a gas dispersion device The gas dispersion device includes a plurality of holes in fluid communication with the upper chamber region and the lower chamber region The method includes supplying an etch gas mixture to the upper chamber region and striking inductively coupled plasma in the upper chamber region by supplying power to the inductive coil The etch gas mixture etches silicon nitride, promotes silicon dioxide passivation and promotes polysilicon passivation, The method includes selectively etching the silicon nitride layer on the substrate and extinguishing the inductively coupled plasma after a predetermined period

Systems and methods for ultrahigh selective nitride etch

Methods and apparatus utilize a rate of drop in pressure upstream of a gas flow controller (GFC) to accurately measure a rate of flow through the GFC. Measurement of the gas flow through the many gas flow controllers in production use today is enabled, without requiring any special or sophisticated pressure regulators or other special components. Various provisions ensure that none of the changes in pressure that occur during or after the measurement perturb the constant flow of gas through the GFC under test.

Method and apparatus for in situ testing of gas flow controllers

A system is provided and includes a substrate processing chamber, one or more injectors, and a controller. The one or more injectors inject an electronegative gas, a baseline electropositive gas, and an additional electropositive gas into the substrate processing chamber. The electronegative gas includes an etch precursor. The additional electropositive gas mixes with and increases electron density of a plasma in the substrate processing chamber. The controller is configured to set an amount, flow rate or pressure of the additional electropositive gas based on at least one of a pressure of the electronegative gas or an electron affinity level of the additional electropositive gas.

System and method for increasing electron density levels in a plasma of a substrate processing system

A mass flow controller comprises: a first flow meter constructed and arranged to measured flow rate of mass through the mass flow controller; a second flow meter constructed and arranged to measure flow rate of mass through the mass flow controller; a control valve constructed and arranged so as to control the flow rate of mass through the mass flow controller in response to a control signal generated as a function of the flow rate as measured by one of the flow meters; and a system controller constructed and arranged to generate the control signal, and to provide an indication when a difference between the flow rate of mass as measured by the first flow meter and the flow rate of mass as measured by the second flow meter exceeds a threshold.

System for and method of monitoring flow through mass flow controllers in real time

A method and apparatus for self-calibrating control of gas flow. The gas flow rate is initially set by controlling, to a high degree of precision, the amount of opening of a flow restriction, where the design of the apparatus containing the flow restriction lends itself to achieving high precision. The gas flow rate is then measured by a pressure rate-of-drop upstream of the flow restriction, and the amount of flow restriction opening is adjusted, if need be, to obtain exactly the desired flow.

Method and apparatus for gas flow control

An apparatus to measure the transient response of a mass flow controller (MFC). The size of a variable orifice, upstream of the MFC, is controlled such that the pressure between the orifice and the MFC is held constant during the entire time that the MFC is going through its transient response. The known relationship between the size of the orifice and the flow through it allows a determination of the transient response of the MFC.

Transient measurements of mass flow controllers

An in-situ gas flow measurement controller measures the temperature and rate of pressure drop upstream from a flow control device (FCD). The controller samples the pressure and temperature data and applies the equivalent of a decimating filter to the data to produce filtered data at a slower sampling rate. The controller derives timestamps by counting ticks from the sampling clock of the A/D converter that is sampling the pressure at regular intervals to ensure the timestamps associated with the pressure samples are accurate and do not contain jitter that is associated with software clocks. The controller additionally normalizes the temperature reading to account for power supply fluctuations, filters out noise from the pressure and temperature readings, and excludes data during periods of instability. It calculates the gas flow rate accounting for possible non-linearities in the pressure measurements, and provides the computed gas flow measurement via one of many possible interfaces.

Method and apparatus for enhancing in-situ gas flow measurement performance

This paper presents a new type of control scheme and device for controlling gas flow into semiconductor process chambers. The key component of the Gas Flow Controller (GFC) is a high-precision valve with an integrated position sensor, which is used to maintain a constant flow rate. A map lookup scheme is employed to adjust the valve position to accommodate the upstream pressure, including any changes or disturbances. The layout of the flow controller also allows for the incorporation of a pressure-volume-time-temperature-based flow measurement, which is a primary standard flow measurement, to confirm and maintain flow accuracy throughout the device's lifetime. The fast response time of the sensors and the high sampling rate in the control loop enables the control of the gas flow within the order of tens of milliseconds.

/pdf/a-new-device-for-highly-accurate-gas-flow-control-with-1lw1vek82t.pdf

Jialing Chen

Papers

Method and apparatus for in situ testing of gas flow controllers

Method and apparatus for gas flow control

Transient measurements of mass flow controllers

Method and apparatus for enhancing in-situ gas flow measurement performance

A new device for highly accurate gas flow control with extremely fast response times