Entity Framework - Code first - Data annotations - Unnecessary foreign key columns

Entity Framework is creating two unnecessary columns in my AccountCompanyRole table.

AccountCompany

public class AccountCompany
{
    [Key, Column(Order = 0), ForeignKey("Account")]
    public int AccountID { get; set; }

    [Key, Column(Order = 1), ForeignKey("Company")]
    public int CompanyID { get; set; }

    public virtual Account Account { get; set; }

    public virtual Company Company { get; set; }

    public virtual ICollection<AccountCompanyRole> AccountCompanyRoles { get; set; }
}

AccountCompanyRoles

public class AccountCompanyRole
{
    [Key, Column(Order = 0), ForeignKey("AccountCompany")]
    public int AccountID { get; set; }

    [Key, Column(Order = 1), ForeignKey("AccountCompany")]
    public int CompanyID { get; set; }

    [Key, Column(Order = 2), ForeignKey("Role")]
    public int RoleID { get; set; }

    public virtual AccountCompany AccountCompany { get; set; }

    public virtual Role Role { get; set; }
}

OnModelCreating

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        modelBuilder.Entity<AccountCompanyRole>()
            .HasRequired(p => p.AccountCompany)
            .WithMany()
            .WillCascadeOnDelete(false);

        base.OnModelCreating(modelBuilder);
    }

Result in DB

As you can see, EF has added two extra foreign keys in AccountCompanyRoles even tho I specified primary key and foreign key in Data Annotations.

Questions

1. How do I prevent it from creating AccountCompany_AccountID and AccountCompany_CompanyID?

2. Is this the best structure for what I am after? Should I instead use one primarykey and put IsUnique index on AccountID and CompanyID? This would probably solve my problem..