Getting error while creating dbo schema programmatically

I am trying to create database,schema and tables through c# code and so far i have successfully created database but getting error while creating schema:

I am trying to create below schema:

1) Person
2) Production
3) Sales
4) dbo

Now some tables have schema as Person and some tables have schema as dbo and so while creating tables i would like that tables to have appropriate schema.

I am not getting error while creating Person,Production and sales schema but i get error while creating schema for dbo.

Error:The specified schema name "dbo" either does not exist or you do not have permission to use it.CREATE SCHEMA failed due to previous errors.

Code: This is my code:

 conn.Open();
 foreach (var item in schemaList)
                    {
                        sqlQuery = "CREATE SCHEMA " + schema;
                        using (SqlCommand cmd = new SqlCommand(sqlQuery, conn))
                    {
                         cmd.CommandTimeout = 0;
                         cmd.ExecuteNonQuery();
                    }
                    }
  conn.Close();

Why does this permission problems doesnt comes in case of creating other schema and why it comes only while creating dbo schema.