problem when trying to create this table in sql, I get an error in the Identity

CREATE TABLE Materia
(codigoMateria INT IDENTITY(1,1) NOT NULL ,
 nombre        VARCHAR(40) NULL ,
 estado        BIT NOT NULL CONSTRAINT DF_Materia_estado DEFAULT (getdate()),

 CONSTRAINT PK_Order PRIMARY KEY  (codigoMateria ),
 CONSTRAINT AK1_Order_OrderNumber UNIQUE  (nombre )
);
INSERT INTO Materia VALUES (1,'Programming',0);
INSERT INTO Materia VALUES (2,'Advance algoritms',0);