Simulation method, simulation program, process control system, simulator, process design method, and mask design method

A non-transitory computer-readable medium storing thereon a simulation program that, when executed by a processor of an information processing apparatus, causes the information processing apparatus to perform operations comprising:

• calculating, based on processing conditions for performing an etching process using plasma on a surface of a wafer covered by a mask having a predetermined mask thickness and aperture ratio, a flux amount of a reaction product that enters the surface of the wafer;
• calculating, based on mask information including the mask thickness and the aperture ratio and the flux amount, an etching rate of the wafer;
• calculating, based on the processing conditions and the etching rate, a dissociation fraction of the reaction product;
• calculating, based on the mask information and the etching rate, a solid angle at a predetermined evaluation point set on the surface of the wafer, the solid angle corresponding to a view area in which plasma space can be seen from the evaluation point;
• calculating, based on the etching rate, the dissociation fraction, the solid angle, and the aperture ratio, a control index for evaluating a shape of the surface of the wafer;
• and
• modifying the etching process based on the calculations.

A process control system, comprising:

• a plurality of etching apparatuses;
• and
• controllers provided to the plurality of etching apparatuses, each of the plurality of controllers including a communication unit and a controller, the communication unit configured to communicate with a server, the controller configured to
• transmit processing conditions for performing an etching process using plasma on a surface of a wafer covered by a mask having a predetermined mask thickness and aperture ratio and mask information including the mask thickness and the aperture ratio,
• control the communication unit to receive, from the server, a control index for evaluating a shape of the surface of the wafer, the control index generated using a flux amount of a reaction product that enters the surface of the wafer, which is calculated based on the processing conditions, an etching rate of the wafer, which is calculated based on the mask information and the flux amount, a dissociation fraction of the reaction product, which is calculated based on the processing conditions and the etching rate, a solid angle at a predetermined evaluation point set on the surface of the wafer, the solid angle corresponding to a view area in which plasma space can be seen from the evaluation point, the solid angle being calculated based on the mask information and the etching rate, and the aperture ratio, and
• control the plurality of etching apparatuses to modify the etching process based on the calculations.

A process control system, comprising:

• a first processing apparatus configured to perform an etching process using plasma on a surface of a wafer;
• and
• an information processing apparatus configured to predict shape development of the wafer, which is caused due to the etching process, the information processing apparatus including
• an input unit configured to acquire processing conditions for performing the etching process using plasma on a surface of a wafer covered by a mask having a predetermined mask thickness and aperture ratio, and
• an arithmetic unit configured
• to calculate, based on the processing conditions, a flux amount of a reaction product that enters the surface of the wafer,
• to calculate, based on mask information including the mask thickness and the aperture ratio and the flux amount, an etching rate of the wafer,
• to calculate, based on the processing conditions and the etching rate, a dissociation fraction of the reaction product,
• to calculate, based on the mask information and the etching rate, a solid angle at a predetermined evaluation point set on the surface of the wafer, the solid angle corresponding to a view area in which plasma space can be seen from the evaluation point,
• to calculate, based on the etching rate, the dissociation fraction, the solid angle, and the aperture ratio, a control index for evaluating a shape of the surface of the wafer, and
• to modify the etching process based on the calculations.

A simulator comprising:

• an input unit configured to acquire processing conditions for performing an etching process using plasma on a surface of a wafer covered by a mask having a predetermined mask thickness and aperture ratio, and
• an arithmetic unit configured
• to calculate, based on the processing conditions, a flux amount of a reaction product that enters the surface of the wafer,
• to calculate, based on mask information including the mask thickness and the aperture ratio and the flux amount, an etching rate of the wafer,
• to calculate, based on the processing conditions and the etching rate, a dissociation fraction of the reaction product,
• to calculate, based on the mask information and the etching rate, a solid angle at a predetermined evaluation point set on the surface of the wafer, the solid angle corresponding to a view area in which plasma space can be seen from the evaluation point,
• to calculate, based on the etching rate, the dissociation fraction, the solid angle, and the aperture ratio, a control index for evaluating a shape of the surface of the wafer, and
• to modify the etching process based on the calculations.

A process design method, comprising:

• acquiring processing conditions for performing an etching process using plasma on a surface of a wafer covered by a mask having a predetermined mask thickness and aperture ratio;
• calculating, based on the processing conditions, a flux amount of a reaction product that enters the surface of the wafer;
• calculating, based on mask information including the mask thickness and the aperture ratio and the flux amount, an etching rate of the wafer;
• calculating, based on the processing conditions and the etching rate, a dissociation fraction of the reaction product;
• calculating, based on the mask information and the etching rate, a solid angle a predetermined evaluation point set on the surface of the wafer, the solid angle corresponding to a view area in which plasma space can be seen from the evaluation point;
• calculating, based on the etching rate, the dissociation fraction, the solid angle, and the aperture ratio, a control index for evaluating a shape of the surface of the wafer;
• and
• changing the processing conditions so that the control index is within a predetermined range based on the calculations, thereby modifying the etching process.

A mask design method, comprising:

• acquiring processing conditions for performing an etching process using plasma on a surface of a wafer covered by a mask having a predetermined mask thickness and aperture ratio;
• calculating, based on the processing conditions, a flux amount of a reaction product that enters the surface of the wafer;
• calculating, based on mask information including the mask thickness and the aperture ratio and the flux amount, an etching rate of the wafer;
• calculating, based on the processing conditions and the etching rate, a dissociation fraction of the reaction product;
• calculating, based on the mask information and the etching rate, a solid angle at a predetermined evaluation point set on the surface of the wafer, the solid angle corresponding to a view area in which plasma space can be seen from the evaluation point;
• calculating, based on the etching rate, the dissociation fraction, the solid angle, and the aperture ratio, a control index for evaluating a shape of the surface of the wafer;
• and
• changing design of the mask so that the control index is within a predetermined range, based on the calculations.