Furnace anneal
Encyclopedia
Furnace annealing is a process used in semiconductor device fabrication which consist of heating multiple semiconductor
wafers
in order to affect their electrical properties. Heat treatments are designed for different effects. Wafers can be heated in order to activate dopant
s, change film to film or film to wafer substrate interfaces, densify deposited films, change states of grown films, repair damage from implants
, move dopants or drive dopants from one film into another or from a film into the wafer substrate.
Furnace anneals may be integrated into other furnace processing steps, such as oxidations, or may be processed on their own.
Furnace anneals are performed by equipment especially built to heat semiconductor
wafers. Furnaces are capable of processing lots of wafers at a time but each process can last between several hours and a day.
Increasingly, furnace anneals are being supplanted by Rapid Thermal Anneal (RTA) or Rapid Thermal Processing (RTP). The reason for this is the relatively long thermal cycles of furnaces causes dopants that are being activated, especially boron, to diffuse farther than is intended. RTP or RTA fixes this by having thermal cycles for each wafer that is of the order of minutes rather than hours for furnace anneals.
Semiconductor
A semiconductor is a material with electrical conductivity due to electron flow intermediate in magnitude between that of a conductor and an insulator. This means a conductivity roughly in the range of 103 to 10−8 siemens per centimeter...
wafers
Wafer (electronics)
A wafer is a thin slice of semiconductor material, such as a silicon crystal, used in the fabrication of integrated circuits and other microdevices...
in order to affect their electrical properties. Heat treatments are designed for different effects. Wafers can be heated in order to activate dopant
Dopant
A dopant, also called a doping agent, is a trace impurity element that is inserted into a substance in order to alter the electrical properties or the optical properties of the substance. In the case of crystalline substances, the atoms of the dopant very commonly take the place of elements that...
s, change film to film or film to wafer substrate interfaces, densify deposited films, change states of grown films, repair damage from implants
Ion implantation
Ion implantation is a materials engineering process by which ions of a material are accelerated in an electrical field and impacted into another solid. This process is used to change the physical, chemical, or electrical properties of the solid...
, move dopants or drive dopants from one film into another or from a film into the wafer substrate.
Furnace anneals may be integrated into other furnace processing steps, such as oxidations, or may be processed on their own.
Furnace anneals are performed by equipment especially built to heat semiconductor
Semiconductor
A semiconductor is a material with electrical conductivity due to electron flow intermediate in magnitude between that of a conductor and an insulator. This means a conductivity roughly in the range of 103 to 10−8 siemens per centimeter...
wafers. Furnaces are capable of processing lots of wafers at a time but each process can last between several hours and a day.
Increasingly, furnace anneals are being supplanted by Rapid Thermal Anneal (RTA) or Rapid Thermal Processing (RTP). The reason for this is the relatively long thermal cycles of furnaces causes dopants that are being activated, especially boron, to diffuse farther than is intended. RTP or RTA fixes this by having thermal cycles for each wafer that is of the order of minutes rather than hours for furnace anneals.
Equipment
- Aviza AVP
- Tokyo Electron alpha
- Kokusai Vertron, Zestone, and ALDINNA
- ASM Advance 400