Title:
SYSTEM FOR UNIFORMIZING THICKNESS OF OXIDE FILM IN WAFER WITHIN FURNACE FOR OXIDIZING SEMICONDUCTOR
Document Type and Number:
Japanese Patent JPS61120427
Kind Code:
A
Abstract:
PURPOSE:To uniformize the thickness of an oxide film formed on a substrate, by controlling the temperature distribution in the circumferential direction of a furnace from a transient state temperature model and an oxide film thickness model of a wafer in the furnace, the models being obtained based on an equation of heat conduction which is formulated taking the radiation into consideration. CONSTITUTION:The thickness of an oxide film of a wafer treated in a patching manner is measured by 3 and the distribution of temperature in a furnace when the wafer is inserted thereinto is detected by 2. The temperature distribution Tr on the furnace walls is determined in accordance with a combination [1tau] of current I supplied to a coil controllable independently from the main coil and provided in the lower portion of the furnace and of time tau during which electricity is supplied. The temperature distribution Tr and the temperature T of the wafer are used for setting a transient temperature model of the wafer dT/dt and a growth model of the oxide film thickness dtox/dt. The combination [1tau] in which an evaluated value [tox1-tox2]<2> representing a difference between the upper film thickness tox1 and the lower film thickness tox2 is minimized is determined with algorithm by 4 and stored in 5. The temperature in the furnace is controlled such that the temperature is distributed unsymmetrically in the circumferential direction of the furnace. According to this construction, no effect is exerted by a jig 1 and an oxide film having a uniform thickness can be formed on the wafer.
Inventors:
MOKUYA KINJI
MATSUBA IKUO
MATSUMOTO KUNIAKI
YOSHINAKA AKIRA
MATSUBA IKUO
MATSUMOTO KUNIAKI
YOSHINAKA AKIRA
Application Number:
JP24067684A
Publication Date:
June 07, 1986
Filing Date:
November 16, 1984
Export Citation:
Assignee:
HITACHI LTD
International Classes:
H01L21/31; H01L21/316; (IPC1-7): H01L21/316
Attorney, Agent or Firm:
Akio Takahashi